Build Your Own Oracle RAC 11g Cluster on Oracle Linux and iSCSI

by Jeffrey Hunter

Learn how to set up and configure an Oracle RAC 11g Release 2 development cluster on Oracle Linux for less than US$2,700.

The information in this guide is not validated by Oracle, is not supported by Oracle, and should only be used at your own risk; it is for educational purposes only.

Updated November 2009

Contents

  1. Introduction
  2. Oracle RAC 11g Overview
  3. Shared-Storage Overview
  4. iSCSI Technology
  5. Hardware and Costs
  6. Install the Linux Operating System
  7. Install Required Linux Packages for Oracle RAC
  8. Network Configuration
  9. Cluster Time Synchronization Service
  10. Install Openfiler
  11. Configure iSCSI Volumes using Openfiler
  12. Configure iSCSI Volumes on Oracle RAC Nodes
  13. Create Job Role Separation Operating System Privileges Groups, Users, and Directories
  14. Logging In to a Remote System Using X Terminal
  15. Configure the Linux Servers for Oracle
  16. Configure RAC Nodes for Remote Access using SSH - (Optional)
  17. All Startup Commands for Both Oracle RAC Nodes
  18. Install and Configure ASMLib 2.0
  19. Download Oracle RAC 11g Release 2 Software
  20. Preinstallation Tasks for Oracle Grid Infrastructure for a Cluster
  21. Install Oracle Grid Infrastructure for a Cluster
  22. Postinstallation Tasks for Oracle Grid Infrastructure for a Cluster
  23. Create ASM Disk Groups for Data and Fast Recovery Area
  24. Install Oracle Database 11g with Oracle Real Application Clusters
  25. Install Oracle Database 11g Examples (formerly Companion)
  26. Create the Oracle Cluster Database
  27. Post Database Creation Tasks - (Optional)
  28. Create / Alter Tablespaces
  29. Verify Oracle Grid Infrastructure and Database Configuration
  30. Starting / Stopping the Cluster
  31. Troubleshooting
  32. Conclusion
  33. Acknowledgements

Downloads for this guide:
 Oracle Enterprise Linux Release 5 Update 4 — (Available for x86 and x86_64)
 Oracle Database 11g Release 2, Grid Infrastructure, Examples — (11.2.0.1.0) — (Available for x86 and x86_64)
 Openfiler 2.3 Respin (21-01-09) — ( openfiler-2.3-x86-disc1.iso -OR- openfiler-2.3-x86_64-disc1.iso)
 ASMLib 2.0 Library RHEL5 - (2.0.4-1) — ( oracleasmlib-2.0.4-1.el5.i386.rpm -OR- oracleasmlib-2.0.4-1.el5.x86_64.rpm)

 


1. Introduction

One of the most efficient ways to become familiar with Oracle Real Application Clusters (RAC) 11g technology is to have access to an actual Oracle RAC 11g cluster. There's no better way to understand its benefits—including fault tolerance, security, load balancing, and scalability—than to experience them directly.

Unfortunately, for many shops, the price of the hardware required for a typical production RAC configuration makes this goal impossible. A small two-node cluster can cost from US$10,000 to well over US$20,000. This cost would not even include the heart of a production RAC environment, the shared storage. In most cases, this would be a Storage Area Network (SAN), which generally start at US$10,000.

For those who want to become familiar with Oracle RAC 11g without a major cash outlay, this guide provides a low-cost alternative to configuring an Oracle RAC 11g Release 2 system using commercial off-the-shelf components and downloadable software at an estimated cost of US$2,200 to US$2,700. The system will consist of a two node cluster, both running Oracle Enterprise Linux (OEL) Release 5 Update 4 for x86_64, Oracle RAC 11g Release 2 for Linux x86_64, and ASMLib 2.0. All shared disk storage for Oracle RAC will be based on iSCSI using Openfiler release 2.3 x86_64 running on a third node (known in this article as the Network Storage Server).

Although this article should work with Red Hat Enterprise Linux, Oracle Enterprise Linux (available for free) will provide the same if not better stability and will already include the ASMLib software packages (with the exception of the ASMLib userspace libraries which is a separate download).

This guide is provided for educational purposes only, so the setup is kept simple to demonstrate ideas and concepts. For example, the shared Oracle Clusterware files (OCR and voting files) and all physical database files in this article will be set up on only one physical disk, while in practice that should be configured on multiple physical drives. In addition, each Linux node will only be configured with two network interfaces — one for the public network ( eth0) and one that will be used for both the Oracle RAC private interconnect "and" the network storage server for shared iSCSI access ( eth1). For a production RAC implementation, the private interconnect should be at least Gigabit (or more) with redundant paths and "only" be used by Oracle to transfer Cluster Manager and Cache Fusion related data. A third dedicated network interface ( eth2, for example) should be configured on another redundant Gigabit network for access to the network storage server (Openfiler).

Oracle Documentation

While this guide provides detailed instructions for successfully installing a complete Oracle RAC 11g system, it is by no means a substitute for the official Oracle documentation (see list below) . In addition to this guide, users should also consult the following Oracle documents to gain a full understanding of alternative configuration options, installation, and administration with Oracle RAC 11g. Oracle's official documentation site is docs.oracle.com.

 



Network Storage Server

Powered by rPath Linux, Openfiler is a free browser-based network storage management utility that delivers file-based Network Attached Storage (NAS) and block-based Storage Area Networking (SAN) in a single framework. The entire software stack interfaces with open source applications such as Apache, Samba, LVM2, ext3, Linux NFS and iSCSI Enterprise Target. Openfiler combines these ubiquitous technologies into a small, easy to manage solution fronted by a powerful web-based management interface.

Openfiler supports CIFS, NFS, HTTP/DAV, FTP, however, we will only be making use of its iSCSI capabilities to implement an inexpensive SAN for the shared storage components required by Oracle RAC 11g. The operating system and Openfiler application will be installed on one internal SATA disk. A second internal 73GB 15K SCSI hard disk will be configured as a single "Volume Group" that will be used for all shared disk storage requirements. The Openfiler server will be configured to use this volume group for iSCSI based storage and will be used in our Oracle RAC 11g configuration to store the shared files required by Oracle grid infrastructure and the Oracle RAC database.

Oracle Grid Infrastructure 11g Release 2 (11.2)

With Oracle grid infrastructure 11g Release 2 (11.2), the Automatic Storage Management (ASM) and Oracle Clusterware software is packaged together in a single binary distribution and installed into a single home directory, which is referred to as the Grid Infrastructure home. You must install the grid infrastructure in order to use Oracle RAC 11g Release 2. Configuration assistants start after the installer interview process that configure ASM and Oracle Clusterware. While the installation of the combined products is called Oracle grid infrastructure, Oracle Clusterware and Automatic Storage Manager remain separate products.

After Oracle grid infrastructure is installed and configured on both nodes in the cluster, the next step will be to install the Oracle RAC software on both Oracle RAC nodes.

In this article, the Oracle grid infrastructure and Oracle RAC software will be installed on both nodes using the optional Job Role Separation configuration. One OS user will be created to own each Oracle software product — " grid" for the Oracle grid infrastructure owner and " oracle" for the Oracle RAC software. Throughout this article, a user created to own the Oracle grid infrastructure binaries is called the grid user. This user will own both the Oracle Clusterware and Oracle Automatic Storage Management binaries. The user created to own the Oracle database binaries (Oracle RAC) will be called the oracle user. Both Oracle software owners must have the Oracle Inventory group ( oinstall) as their primary group, so that each Oracle software installation owner can write to the central inventory (oraInventory), and so that OCR and Oracle Clusterware resource permissions are set correctly. The Oracle RAC software owner must also have the OSDBA group and the optional OSOPER group as secondary groups.

Automatic Storage Management and Oracle Clusterware Files

As previously mentioned, Automatic Storage Management (ASM) is now fully integrated with Oracle Clusterware in the Oracle grid infrastructure. Oracle ASM and Oracle Database 11g Release 2 provide a more enhanced storage solution from previous releases. Part of this solution is the ability to store the Oracle Clusterware files; namely the Oracle Cluster Registry (OCR) and the Voting Files (VF — also known as the Voting Disks) on ASM. This feature enables ASM to provide a unified storage solution, storing all the data for the clusterware and the database, without the need for third-party volume managers or cluster file systems.

Just like database files, Oracle Clusterware files are stored in an ASM disk group and therefore utilize the ASM disk group configuration with respect to redundancy. For example, a Normal Redundancy ASM disk group will hold a two-way-mirrored OCR. A failure of one disk in the disk group will not prevent access to the OCR. With a High Redundancy ASM disk group (three-way-mirrored), two independent disks can fail without impacting access to the OCR. With External Redundancy, no protection is provided by Oracle.

Oracle only allows one OCR per disk group in order to protect against physical disk failures. When configuring Oracle Clusterware files on a production system, Oracle recommends using either normal or high redundancy ASM disk groups. If disk mirroring is already occurring at either the OS or hardware level, you can use external redundancy.

The Voting Files are managed in a similar way to the OCR. They follow the ASM disk group configuration with respect to redundancy, but are not managed as normal ASM files in the disk group. Instead, each voting disk is placed on a specific disk in the disk group. The disk and the location of the Voting Files on the disks are stored internally within Oracle Clusterware.

The following example describes how the Oracle Clusterware files are stored in ASM after installing Oracle grid infrastructure using this guide. To view the OCR, use ASMCMD:

[grid@racnode1 ~]$  
                         asmcmd
ASMCMD>  
                         ls -l +CRS/racnode-cluster/OCRFILE
Type     Redund  Striped  Time             Sys  Name
OCRFILE  UNPROT  COARSE   NOV 22 12:00:00  Y    REGISTRY.255.703024853
                      
+CRS/racnode-cluster/OCRFILEREGISTRY.255.703024853crsctl query css votedisk
[grid@racnode1 ~]$  
                         crsctl query css votedisk
##  STATE    File Universal Id                File Name Disk group
--  -----    -----------------                --------- ---------
 1. ONLINE   4cbbd0de4c694f50bfd3857ebd8ad8c4 (ORCL:CRSVOL1) [CRS]
Located 1 voting disk(s).
                      


If you decide against using ASM for the OCR and voting disk files, Oracle Clusterware still allows these files to be stored on a cluster file system like Oracle Cluster File System release 2 (OCFS2) or a NFS system. Please note that installing Oracle Clusterware files on raw or block devices is no longer supported, unless an existing system is being upgraded.

Previous versions of this guide used OCFS2 for storing the OCR and voting disk files. This guide will store the OCR and voting disk files on ASM in an ASM disk group named +CRS using external redundancy which is one OCR location and one voting disk location. The ASM disk group should be be created on shared storage and be at least 2GB in size.

 

The Oracle physical database files (data, online redo logs, control files, archived redo logs) will be installed on ASM in an ASM disk group named +RACDB_DATA while the Fast Recovery Area will be created in a separate ASM disk group named +FRA.

The two Oracle RAC nodes and the network storage server will be configured as follows:

Nodes
Node Name Instance Name Database Name Processor RAM Operating System
racnode1 racdb1 racdb.idevelopment.info 1 x Dual Core Intel Xeon, 3.00 GHz 4GB OEL 5.4 - (x86_64)
racnode2 racdb2 1 x Dual Core Intel Xeon, 3.00 GHz 4GB OEL 5.4 - (x86_64)
openfiler1     2 x Intel Xeon, 3.00 GHz 6GB Openfiler 2.3 - (x86_64)
Network Configuration
Node Name Public IP Private IP Virtual IP SCAN Name SCAN IP
racnode1 192.168.1.151 192.168.2.151 192.168.1.251 racnode-cluster-scan 192.168.1.187
racnode2 192.168.1.152 192.168.2.152 192.168.1.252
openfiler1 192.168.1.195 192.168.2.195  
Oracle Software Components
Software Component OS User Primary Group Supplementary Groups Home Directory Oracle Base / Oracle Home
Grid Infrastructure grid oinstall asmadmin, asmdba, asmoper /home/grid /u01/app/grid
/u01/app/11.2.0/grid
Oracle RAC oracle oinstall dba, oper, asmdba /home/oracle /u01/app/oracle
/u01/app/oracle/product/11.2.0/dbhome_1
Storage Components
Storage Component File System Volume Size ASM Volume Group Name ASM Redundancy Openfiler Volume Name
OCR/Voting Disk ASM 2GB +CRS External racdb-crs1
Database Files ASM 32GB +RACDB_DATA External racdb-data1
Fast Recovery Area ASM 32GB +FRA External racdb-fra1

This article is only designed to work as documented with absolutely no substitutions. The only exception here is the choice of vendor hardware (i.e. machines, networking equipment, and internal / external hard drives). Ensure that the hardware you purchase from the vendor is supported on Enterprise Linux 5 and Openfiler 2.3 (Final Release).

If you are looking for an example that takes advantage of Oracle RAC 10g release 2 with Oracle Enterprise Linux 5.3 using iSCSI, click here.

 


2. Oracle RAC 11g Overview

Before introducing the details for building a RAC cluster, it might be helpful to first clarify what a cluster is. A cluster is a group of two or more interconnected computers or servers that appear as if they are one server to end users and applications and generally share the same set of physical disks. The key benefit of clustering is to provide a highly available framework where the failure of one node (for example a database server running an instance of Oracle) does not bring down an entire application. In the case of failure with one of the servers, the other surviving server (or servers) can take over the workload from the failed server and the application continues to function normally as if nothing has happened.

The concept of clustering computers actually started several decades ago. The first successful cluster product was developed by DataPoint in 1977 named ARCnet. The ARCnet product enjoyed much success by academia types in research labs, but didn't really take off in the commercial market. It wasn't until the 1980's when Digital Equipment Corporation (DEC) released its VAX cluster product for the VAX/VMS operating system.

With the release of Oracle 6 for the Digital VAX cluster product, Oracle was the first commercial database to support clustering at the database level. It wasn't long, however, before Oracle realized the need for a more efficient and scalable distributed lock manager (DLM) as the one included with the VAX/VMS cluster product was not well suited for database applications. Oracle decided to design and write their own DLM for the VAX/VMS cluster product which provided the fine-grain block level locking required by the database. Oracle's own DLM was included in Oracle 6.2 which gave birth to Oracle Parallel Server (OPS) - the first database to run the parallel server.

By Oracle 7, OPS was extended to included support for not only the VAX/VMS cluster product but also with most flavors of UNIX. This framework required vendor-supplied clusterware which worked well, but made for a complex environment to setup and manage given the multiple layers involved. By Oracle8, Oracle introduced a generic lock manager that was integrated into the Oracle kernel. In later releases of Oracle, this became known as the Integrated Distributed Lock Manager (IDLM) and relied on an additional layer known as the Operating System Dependant (OSD) layer. This new model paved the way for Oracle to not only have their own DLM, but to also create their own clusterware product in future releases.

Oracle Real Application Clusters (RAC), introduced with Oracle9i, is the successor to Oracle Parallel Server. Using the same IDLM, Oracle 9i could still rely on external clusterware but was the first release to include their own clusterware product named Cluster Ready Services (CRS). With Oracle 9i, CRS was only available for Windows and Linux. By Oracle 10g release 1, Oracle's clusterware product was available for all operating systems and was the required cluster technology for Oracle RAC. With the release of Oracle Database 10g Release 2 (10.2), Cluster Ready Services was renamed to Oracle Clusterware. When using Oracle 10g or higher, Oracle Clusterware is the only clusterware that you need for most platforms on which Oracle RAC operates (except for Tru cluster, in which case you need vendor clusterware). You can still use clusterware from other vendors if the clusterware is certified, but keep in mind that Oracle RAC still requires Oracle Clusterware as it is fully integrated with the database software. This guide uses Oracle Clusterware which as of 11g Release 2 (11.2), is now a component of Oracle grid infrastructure.

Like OPS, Oracle RAC allows multiple instances to access the same database (storage) simultaneously. RAC provides fault tolerance, load balancing, and performance benefits by allowing the system to scale out, and at the same time since all instances access the same database, the failure of one node will not cause the loss of access to the database.

At the heart of Oracle RAC is a shared disk subsystem. Each instance in the cluster must be able to access all of the data, redo log files, control files and parameter file for all other instances in the cluster. The data disks must be globally available in order to allow all instances to access the database. Each instance has its own redo log files and UNDO tablespace that are locally read-writeable. The other instances in the cluster must be able to access them (read-only) in order to recover that instance in the event of a system failure. The redo log files for an instance are only writeable by that instance and will only be read from another instance during system failure. The UNDO, on the other hand, is read all the time during normal database operation (e.g. for CR fabrication).

A big difference between Oracle RAC and OPS is the addition of Cache Fusion. With OPS a request for data from one instance to another required the data to be written to disk first, then the requesting instance can read that data (after acquiring the required locks). This process was called disk pinging. With cache fusion, data is passed along a high-speed interconnect using a sophisticated locking algorithm.

Not all database clustering solutions use shared storage. Some vendors use an approach known as a Federated Cluster, in which data is spread across several machines rather than shared by all. With Oracle RAC, however, multiple instances use the same set of disks for storing data. Oracle's approach to clustering leverages the collective processing power of all the nodes in the cluster and at the same time provides failover security.

Pre-configured Oracle RAC solutions are available from vendors such as Dell, IBM and HP for production environments. This article, however, focuses on putting together your own Oracle RAC 11g environment for development and testing by using Linux servers and a low cost shared disk solution; iSCSI.

For more background about Oracle RAC, visit the Oracle RAC Product Center on OTN.

 


3. Shared-Storage Overview

Today, fibre channel is one of the most popular solutions for shared storage. As mentioned earlier, fibre channel is a high-speed serial-transfer interface that is used to connect systems and storage devices in either point-to-point (FC-P2P), arbitrated loop (FC-AL), or switched topologies (FC-SW). Protocols supported by Fibre Channel include SCSI and IP. Fibre channel configurations can support as many as 127 nodes and have a throughput of up to 2.12 Gigabits per second in each direction, and 4.25 Gbps is expected.

Fibre channel, however, is very expensive. Just the fibre channel switch alone can start at around US$1,000. This does not even include the fibre channel storage array and high-end drives, which can reach prices of about US$300 for a single 36GB drive. A typical fibre channel setup which includes fibre channel cards for the servers is roughly US$10,000, which does not include the cost of the servers that make up the cluster.

A less expensive alternative to fibre channel is SCSI. SCSI technology provides acceptable performance for shared storage, but for administrators and developers who are used to GPL-based Linux prices, even SCSI can come in over budget, at around US$2,000 to US$5,000 for a two-node cluster.

Another popular solution is the Sun NFS (Network File System) found on a NAS. It can be used for shared storage but only if you are using a network appliance or something similar. Specifically, you need servers that guarantee direct I/O over NFS, TCP as the transport protocol, and read/write block sizes of 32K. See the Certify page on Oracle Metalink for supported Network Attached Storage (NAS) devices that can be used with Oracle RAC. One of the key drawbacks that has limited the benefits of using NFS and NAS for database storage has been performance degradation and complex configuration requirements. Standard NFS client software (client systems that use the operating system provided NFS driver) is not optimized for Oracle database file I/O access patterns. With the introduction of Oracle 11g, a new feature known as Direct NFS Client integrates the NFS client functionality directly in the Oracle software. Through this integration, Oracle is able to optimize the I/O path between the Oracle software and the NFS server resulting in significant performance gains. Direct NFS Client can simplify, and in many cases automate, the performance optimization of the NFS client configuration for database workloads. To learn more about Direct NFS Client, see the Oracle White Paper entitled " Oracle Database 11g Direct NFS Client ".

The shared storage that will be used for this article is based on iSCSI technology using a network storage server installed with Openfiler. This solution offers a low-cost alternative to fibre channel for testing and educational purposes, but given the low-end hardware being used, it should not be used in a production environment.

 


4. iSCSI Technology

For many years, the only technology that existed for building a network based storage solution was a Fibre Channel Storage Area Network (FC SAN). Based on an earlier set of ANSI protocols called Fiber Distributed Data Interface (FDDI), Fibre Channel was developed to move SCSI commands over a storage network.

Several of the advantages to FC SAN include greater performance, increased disk utilization, improved availability, better scalability, and most important to us — support for server clustering! Still today, however, FC SANs suffer from three major disadvantages. The first is price. While the costs involved in building a FC SAN have come down in recent years, the cost of entry still remains prohibitive for small companies with limited IT budgets. The second is incompatible hardware components. Since its adoption, many product manufacturers have interpreted the Fibre Channel specifications differently from each other which has resulted in scores of interconnect problems. When purchasing Fibre Channel components from a common manufacturer, this is usually not a problem. The third disadvantage is the fact that a Fibre Channel network is not Ethernet! It requires a separate network technology along with a second set of skill sets that need to exist with the data center staff.

With the popularity of Gigabit Ethernet and the demand for lower cost, Fibre Channel has recently been given a run for its money by iSCSI-based storage systems. Today, iSCSI SANs remain the leading competitor to FC SANs.

Ratified on February 11, 2003 by the Internet Engineering Task Force (IETF), the Internet Small Computer System Interface, better known as iSCSI, is an Internet Protocol (IP)-based storage networking standard for establishing and managing connections between IP-based storage devices, hosts, and clients. iSCSI is a data transport protocol defined in the SCSI-3 specifications framework and is similar to Fibre Channel in that it is responsible for carrying block-level data over a storage network. Block-level communication means that data is transferred between the host and the client in chunks called blocks. Database servers depend on this type of communication (as opposed to the file level communication used by most NAS systems) in order to work properly. Like a FC SAN, an iSCSI SAN should be a separate physical network devoted entirely to storage, however, its components can be much the same as in a typical IP network (LAN).

While iSCSI has a promising future, many of its early critics were quick to point out some of its inherent shortcomings with regards to performance. The beauty of iSCSI is its ability to utilize an already familiar IP network as its transport mechanism. The TCP/IP protocol, however, is very complex and CPU intensive. With iSCSI, most of the processing of the data (both TCP and iSCSI) is handled in software and is much slower than Fibre Channel which is handled completely in hardware. The overhead incurred in mapping every SCSI command onto an equivalent iSCSI transaction is excessive. For many the solution is to do away with iSCSI software initiators and invest in specialized cards that can offload TCP/IP and iSCSI processing from a server's CPU. These specialized cards are sometimes referred to as an iSCSI Host Bus Adaptor (HBA) or a TCP Offload Engine (TOE) card. Also consider that 10-Gigabit Ethernet is a reality today!

As with any new technology, iSCSI comes with its own set of acronyms and terminology. For the purpose of this article, it is only important to understand the difference between an iSCSI initiator and an iSCSI target.

iSCSI Initiator

Basically, an iSCSI initiator is a client device that connects and initiates requests to some service offered by a server (in this case an iSCSI target). The iSCSI initiator software will need to exist on each of the Oracle RAC nodes ( racnode1 and racnode2).

An iSCSI initiator can be implemented using either software or hardware. Software iSCSI initiators are available for most major operating system platforms. For this article, we will be using the free Linux Open-iSCSI software driver found in the iscsi-initiator-utils RPM. The iSCSI software initiator is generally used with a standard network interface card (NIC) — a Gigabit Ethernet card in most cases. A hardware initiator is an iSCSI HBA (or a TCP Offload Engine (TOE) card), which is basically just a specialized Ethernet card with a SCSI ASIC on-board to offload all the work (TCP and SCSI commands) from the system CPU. iSCSI HBAs are available from a number of vendors, including Adaptec, Alacritech, Intel, and QLogic.

iSCSI Target

An iSCSI target is the "server" component of an iSCSI network. This is typically the storage device that contains the information you want and answers requests from the initiator(s). For the purpose of this article, the node openfiler1 will be the iSCSI target.

So with all of this talk about iSCSI, does this mean the death of Fibre Channel anytime soon? Probably not. Fibre Channel has clearly demonstrated its capabilities over the years with its capacity for extremely high speeds, flexibility, and robust reliability. Customers who have strict requirements for high performance storage, large complex connectivity, and mission critical reliability will undoubtedly continue to choose Fibre Channel.

Before closing out this section, I thought it would be appropriate to present the following chart that shows speed comparisons of the various types of disk interfaces and network technologies. For each interface, I provide the maximum transfer rates in kilobits (kb), kilobytes (KB), megabits (Mb), megabytes (MB), gigabits (Gb), and gigabytes (GB) per second with some of the more common ones highlighted in grey.

 

Disk Interface / Network / BUS Speed
Kb KB Mb MB Gb GB
Serial 115 14.375 0.115 0.014    
Parallel (standard) 920 115 0.92 0.115    
10Base-T Ethernet     10 1.25    
IEEE 802.11b wireless Wi-Fi (2.4 GHz band)     11 1.375    
USB 1.1     12 1.5    
Parallel (ECP/EPP)     24 3    
SCSI-1     40 5    
IEEE 802.11g wireless WLAN (2.4 GHz band)     54 6.75    
SCSI-2 (Fast SCSI / Fast Narrow SCSI)     80 10    
100Base-T Ethernet (Fast Ethernet)     100 12.5    
ATA/100 (parallel)     100 12.5    
IDE     133.6 16.7    
Fast Wide SCSI (Wide SCSI)     160 20    
Ultra SCSI (SCSI-3 / Fast-20 / Ultra Narrow)     160 20    
Ultra IDE     264 33    
Wide Ultra SCSI (Fast Wide 20)     320 40    
Ultra2 SCSI     320 40    
FireWire 400 - (IEEE1394a)     400 50    
USB 2.0     480 60    
Wide Ultra2 SCSI     640 80    
Ultra3 SCSI     640 80    
FireWire 800 - (IEEE1394b)     800 100    
Gigabit Ethernet     1000 125 1  
PCI - (33 MHz / 32-bit)     1064 133 1.064  
Serial ATA I - (SATA I)     1200 150 1.2  
Wide Ultra3 SCSI     1280 160 1.28  
Ultra160 SCSI     1280 160 1.28  
PCI - (33 MHz / 64-bit)     2128 266 2.128  
PCI - (66 MHz / 32-bit)     2128 266 2.128  
AGP 1x - (66 MHz / 32-bit)     2128 266 2.128  
Serial ATA II - (SATA II)     2400 300 2.4  
Ultra320 SCSI     2560 320 2.56  
FC-AL Fibre Channel     3200 400 3.2  
PCI-Express x1 - (bidirectional)     4000 500 4  
PCI - (66 MHz / 64-bit)     4256 532 4.256  
AGP 2x - (133 MHz / 32-bit)     4264 533 4.264  
Serial ATA III - (SATA III)     4800 600 4.8  
PCI-X - (100 MHz / 64-bit)     6400 800 6.4  
PCI-X - (133 MHz / 64-bit)       1064 8.512 1
AGP 4x - (266 MHz / 32-bit)       1066 8.528 1
10G Ethernet - (IEEE 802.3ae)       1250 10 1.25
PCI-Express x4 - (bidirectional)       2000 16 2
AGP 8x - (533 MHz / 32-bit)       2133 17.064 2.1
PCI-Express x8 - (bidirectional)       4000 32 4
PCI-Express x16 - (bidirectional)       8000 64 8

 


5. Hardware and Costs

The hardware used to build our example Oracle RAC 11g environment consists of three Linux servers (two Oracle RAC nodes and one Network Storage Server) and components that can be purchased at many local computer stores or over the Internet.

Oracle RAC Node 1 - (racnode1)
Dell PowerEdge T100
  • Dual Core Intel(R) Xeon(R) E3110, 3.0 GHz, 6MB Cache, 1333MHz
  • 4GB, DDR2, 800MHz
  • 160GB 7.2K RPM SATA 3Gbps Hard Drive
  • Integrated Graphics - (ATI ES1000)
  • Integrated Gigabit Ethernet - (Broadcom(R) NetXtreme IITM 5722)
  • 16x DVD Drive
  • No Keyboard, Monitor, or Mouse - (Connected to KVM Switch)
US$450
1 - Ethernet LAN Card

 

Used for RAC interconnect to racnode2 and Openfiler networked storage.

 

Each Linux server for Oracle RAC should contain two NIC adapters. The Dell PowerEdge T100 includes an embedded Broadcom(R) NetXtreme IITM 5722 Gigabit Ethernet NIC that will be used to connect to the public network. A second NIC adapter will be used for the private network (RAC interconnect and Openfiler networked storage). Select the appropriate NIC adapter that is compatible with the maximum data transmission speed of the network switch to be used for the private network. For the purpose of this article, I used a Gigabit Ethernet switch (and a 1Gb Ethernet card) for the private network.

 

     Gigabit Ethernet
US$90
Oracle RAC Node 2 - (racnode2)
Dell PowerEdge T100
  • Dual Core Intel(R) Xeon(R) E3110, 3.0 GHz, 6MB Cache, 1333MHz
  • 4GB, DDR2, 800MHz
  • 160GB 7.2K RPM SATA 3Gbps Hard Drive
  • Integrated Graphics - (ATI ES1000)
  • Integrated Gigabit Ethernet - (Broadcom(R) NetXtreme IITM 5722)
  • 16x DVD Drive
  • No Keyboard, Monitor, or Mouse - (Connected to KVM Switch)
US$450
1 - Ethernet LAN Card

 

Used for RAC interconnect to racnode1 and Openfiler networked storage.

 

Each Linux server for Oracle RAC should contain two NIC adapters. The Dell PowerEdge T100 includes an embedded Broadcom(R) NetXtreme IITM 5722 Gigabit Ethernet NIC that will be used to connect to the public network. A second NIC adapter will be used for the private network (RAC interconnect and Openfiler networked storage). Select the appropriate NIC adapter that is compatible with the maximum data transmission speed of the network switch to be used for the private network. For the purpose of this article, I used a Gigabit Ethernet switch (and a 1Gb Ethernet card) for the private network.

 

     Gigabit Ethernet
US$90
Network Storage Server - (openfiler1)
Dell PowerEdge 1800
  • Dual 3.0GHz Xeon / 1MB Cache / 800FSB (SL7PE)
  • 6GB of ECC Memory
  • 500GB SATA Internal Hard Disk
  • 73GB 15K SCSI Internal Hard Disk
  • Integrated Graphics
  • Single embedded Intel 10/100/1000 Gigabit NIC
  • 16x DVD Drive
  • No Keyboard, Monitor, or Mouse - (Connected to KVM Switch)

Note: The operating system and Openfiler application will be installed on the 500GB internal SATA disk. A second internal 73GB 15K SCSI hard disk will be configured for the database storage. The Openfiler server will be configured to use this second hard disk for iSCSI based storage and will be used in our Oracle RAC 11g configuration to store the shared files required by Oracle Clusterware as well as the clustered database files.

Please be aware that any type of hard disk (internal or external) should work for database storage as long as it can be recognized by the network storage server (Openfiler) and has adequate space. For example, I could have made an extra partition on the 500GB internal SATA disk for the iSCSI target, but decided to make use of the faster SCSI disk for this example.

US$800
1 - Ethernet LAN Card

 

Used for networked storage on the private network.

 

The Network Storage Server (Openfiler server) should contain two NIC adapters. The Dell PowerEdge 1800 machine included an integrated 10/100/1000 Ethernet adapter that will be used to connect to the public network. The second NIC adapter will be used for the private network (Openfiler networked storage). Select the appropriate NIC adapter that is compatible with the maximum data transmission speed of the network switch to be used for the private network. For the purpose of this article, I used a Gigabit Ethernet switch (and 1Gb Ethernet card) for the private network.

 

     Gigabit Ethernet
US$125
Miscellaneous Components
1 - Ethernet Switch

 

Used for the interconnect between racnode1-priv and racnode2-priv which will be on the 192.168.2.0 network. This switch will also be used for network storage traffic for Openfiler. For the purpose of this article, I used a Gigabit Ethernet switch (and 1Gb Ethernet cards) for the private network.

 

     Gigabit Ethernet
US$50
6 - Network Cables US$10
US$10
US$10
US$10
US$10
US$10
Optional Components
KVM Switch

 

This guide requires access to the console of all nodes (servers) in order to install the operating system and perform several of the configuration tasks. When managing a very small number of servers, it might make sense to connect each server with its own monitor, keyboard, and mouse in order to access its console. However, as the number of servers to manage increases, this solution becomes unfeasible. A more practical solution would be to configure a dedicated computer which would include a single monitor, keyboard, and mouse that would have direct access to the console of each server. This solution is made possible using a Keyboard, Video, Mouse Switch —better known as a KVM Switch. A KVM switch is a hardware device that allows a user to control multiple computers from a single keyboard, video monitor and mouse. Avocent provides a high quality and economical 4-port switch which includes four 6' cables:

For a detailed explanation and guide on the use and KVM switches, please see the article " KVM Switches For the Home and the Enterprise".

US$340
Total    US$2,455  

We are about to start the installation process. Now that we have talked about the hardware that will be used in this example, let's take a conceptual look at what the environment would look like after connecting all of the hardware components (click on the graphic below to view larger image):

 



Figure 1: Architecture

As we start to go into the details of the installation, note that most of the tasks within this document will need to be performed on both Oracle RAC nodes (racnode1 and racnode2). I will indicate at the beginning of each section whether or not the task(s) should be performed on both Oracle RAC nodes or on the network storage server (openfiler1).

 


6. Install the Linux Operating System

Perform the following installation on both Oracle RAC nodes in the cluster.

This section provides a summary of the screens used to install the Linux operating system. This guide is designed to work with Oracle Enterprise Linux release 5 update 4 for x86_64 and follows Oracle's suggestion of performing a "default RPMs" installation type to ensure all expected Linux O/S packages are present for a successful Oracle RDBMS installation.

Before installing the Oracle Enterprise Linux operating system on both Oracle RAC nodes, you should have both NIC interface cards installed that will be used for the public and private network.

Download the following ISO images for Oracle Enterprise Linux release 5 update 4 for either x86 or x86_64 depending on your hardware architecture.

Oracle Software Delivery Cloud for Oracle Enterprise Linux

32-bit (x86) Installations

 

  • V17787-01.zip   (582 MB)
  • V17789-01.zip   (612 MB)
  • V17790-01.zip   (620 MB)
  • V17791-01.zip   (619 MB)
  • V17792-01.zip   (267 MB)


After downloading the Oracle Enterprise Linux operating system, unzip each of the files. You will then have the following ISO images which will need to be burned to CDs:

 

  • Enterprise-R5-U4-Server-i386-disc1.iso
  • Enterprise-R5-U4-Server-i386-disc2.iso
  • Enterprise-R5-U4-Server-i386-disc3.iso
  • Enterprise-R5-U4-Server-i386-disc4.iso
  • Enterprise-R5-U4-Server-i386-disc5.iso


Note: If the Linux RAC nodes have a DVD installed, you may find it more convenient to make use of the single DVD image:

 

  • V17793-01.zip   (2.7 GB)


Unzip the single DVD image file and burn it to a DVD:

 

  • Enterprise-R5-U4-Server-i386-dvd.iso


64-bit (x86_64) Installations

 

  • V17795-01.zip   (580 MB)
  • V17796-01.zip   (615 MB)
  • V17797-01.zip   (605 MB)
  • V17798-01.zip   (616 MB)
  • V17799-01.zip   (597 MB)
  • V17800-01.zip   (198 MB)


After downloading the Oracle Enterprise Linux operating system, unzip each of the files. You will then have the following ISO images which will need to be burned to CDs:

 

  • Enterprise-R5-U4-Server-x86_64-disc1.iso
  • Enterprise-R5-U4-Server-x86_64-disc2.iso
  • Enterprise-R5-U4-Server-x86_64-disc3.iso
  • Enterprise-R5-U4-Server-x86_64-disc4.iso
  • Enterprise-R5-U4-Server-x86_64-disc5.iso
  • Enterprise-R5-U4-Server-x86_64-disc6.iso


Note: If the Linux RAC nodes have a DVD installed, you may find it more convenient to make use of the single DVD image:

 

  • V17794-01.zip   (3.2 GB)


Unzip the single DVD image file and burn it to a DVD:

 

  • Enterprise-R5-U4-Server-x86_64-dvd.iso


If you are downloading the above ISO files to a MS Windows machine, there are many options for burning these images (ISO files) to a CD/DVD. You may already be familiar with and have the proper software to burn images to a CD/DVD. If you are not familiar with this process and do not have the required software to burn images to a CD/DVD, here are just two (of many) software packages that can be used:

 



After downloading and burning the Oracle Enterprise Linux images (ISO files) to CD/DVD, insert OEL Disk #1 into the first server ( racnode1 in this example), power it on, and answer the installation screen prompts as noted below. After completing the Linux installation on the first node, perform the same Linux installation on the second node while substituting the node name racnode1 for racnode2 and the different IP addresses where appropriate.

Boot Screen
The first screen is the Oracle Enterprise Linux boot screen. At the boot: prompt, hit [Enter] to start the installation process.

Media Test
When asked to test the CD media, tab over to [Skip] and hit [Enter]. If there were any errors, the media burning software would have warned us. After several seconds, the installer should then detect the video card, monitor, and mouse. The installer then goes into GUI mode.

Welcome to Oracle Enterprise Linux
At the welcome screen, click [Next] to continue.

Language / Keyboard Selection
The next two screens prompt you for the Language and Keyboard settings. Make the appropriate selections for your configuration.

Detect Previous Installation
Note that if the installer detects a previous version of Oracle Enterprise Linux, it will ask if you would like to "Install Enterprise Linux" or "Upgrade an existing Installation". Always select to "Install Enterprise Linux".

Disk Partitioning Setup
Select [Remove all partitions on selected drives and create default layout] and check the option to [Review and modify partitioning layout]. Click [Next] to continue.

You will then be prompted with a dialog window asking if you really want to remove all Linux partitions. Click [Yes] to acknowledge this warning.

Partitioning
The installer will then allow you to view (and modify if needed) the disk partitions it automatically selected. For most automatic layouts, the installer will choose 100MB for /boot, double the amount of RAM (systems with <= 2,048MB RAM) or an amount equal to RAM (systems with > 2,048MB RAM) for swap, and the rest going to the root ( /) partition. Starting with RHEL 4, the installer will create the same disk configuration as just noted but will create them using the Logical Volume Manager (LVM). For example, it will partition the first hard drive ( /dev/sda for my configuration) into two partitions — one for the /boot partition ( /dev/sda1) and the remainder of the disk dedicate to a LVM named VolGroup00 ( /dev/sda2). The LVM Volume Group (VolGroup00) is then partitioned into two LVM partitions - one for the root filesystem ( /) and another for swap.

The main concern during the partitioning phase is to ensure enough swap space is allocated as required by Oracle (which is a multiple of the available RAM). The following is Oracle's minimum requirement for swap space:

 

Available RAM Swap Space Required
Between 1,024MB and 2,048MB 1.5 times the size of RAM
Between 2,049MB and 8,192MB Equal to the size of RAM
More than 8,192MB 0.75 times the size of RAM


For the purpose of this install, I will accept all automatically preferred sizes. (Including 5,952MB for swap since I have 4GB of RAM installed.)

If for any reason, the automatic layout does not configure an adequate amount of swap space, you can easily change that from this screen. To increase the size of the swap partition, [Edit] the volume group VolGroup00. This will bring up the "Edit LVM Volume Group: VolGroup00" dialog. First, [Edit] and decrease the size of the root file system ( /) by the amount you want to add to the swap partition. For example, to add another 512MB to swap, you would decrease the size of the root file system by 512MB (i.e. 36,032MB - 512MB = 35,520MB). Now add the space you decreased from the root file system (512MB) to the swap partition. When completed, click [OK] on the "Edit LVM Volume Group: VolGroup00" dialog.

Once you are satisfied with the disk layout, click [Next] to continue.

Boot Loader Configuration
The installer will use the GRUB boot loader by default. To use the GRUB boot loader, accept all default values and click [Next] to continue.

Network Configuration
I made sure to install both NIC interfaces (cards) in each of the Linux machines before starting the operating system installation. This screen should have successfully detected each of the network devices. Since we will be using this machine to host an Oracle database, there will be several changes that need to be made to the network configuration. The settings you make here will, of course, depend on your network configuration. The key point to make is that the machine should never be configured with DHCP since it will be used to host the Oracle database server. You will need to configure the machine with static IP addresses. You will also need to configure the server with a real host name.

First, make sure that each of the network devices are checked to [Active on boot]. The installer may choose to not activate eth1 by default.

Second, [Edit] both eth0 and eth1 as follows. Verify that the option "Enable IPv4 support" is selected. Click off the option to use "Dynamic IP configuration (DHCP)" by selecting the "Manual configuration" radio button and configure a static IP address and Netmask for your environment. Click off the option to "Enable IPv6 support". You may choose to use different IP addresses for both eth0 and eth1 that I have documented in this guide and that is OK. Put eth1 (the interconnect) on a different subnet than eth0 (the public network):

eth0:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to use [Dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.1.151
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

eth1:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to use [Dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.2.151
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

Continue by manually setting your hostname. I used " racnode1" for the first node and " racnode2" for the second. Finish this dialog off by supplying your gateway and DNS servers.

Time Zone Selection
Select the appropriate time zone for your environment and click [Next] to continue.

Set Root Password
Select a root password and click [Next] to continue.

Package Installation Defaults
By default, Oracle Enterprise Linux installs most of the software required for a typical server. There are several other packages (RPMs), however, that are required to successfully install the Oracle software. The installer includes a "Customize software" selection that allows the addition of RPM groupings such as "Development Libraries" or "Legacy Library Support". The addition of such RPM groupings is not an issue. De-selecting any "default RPM" groupings or individual RPMs, however, can result in failed Oracle grid infrastructure and Oracle RAC installation attempts.

For the purpose of this article, select the radio button [Customize now] and click [Next] to continue.

This is where you pick the packages to install. Most of the packages required for the Oracle software are grouped into "Package Groups" (i.e. Application -> Editors). Since these nodes will be hosting the Oracle grid infrastructure and Oracle RAC software, verify that at least the following package groups are selected for install. For many of the Linux package groups, not all of the packages associated with that group get selected for installation. (Note the "Optional packages" button after selecting a package group.) So although the package group gets selected for install, some of the packages required by Oracle do not get installed. In fact, there are some packages that are required by Oracle that do not belong to any of the available package groups (i.e. libaio-devel). Not to worry. A complete list of required packages for Oracle grid infrastructure 11g Release 2 and Oracle RAC 11g Release 2 for Oracle Enterprise Linux 5 will be provided in the next section. These packages will need to be manually installed from the Oracle Enterprise Linux CDs after the operating system install. For now, install the following package groups:

 

  • Desktop Environments
    • GNOME Desktop Environment
  • Applications
    • Editors
    • Graphical Internet
    • Text-based Internet
  • Development
    • Development Libraries
    • Development Tools
    • Legacy Software Development
  • Servers
    • Server Configuration Tools
  • Base System
    • Administration Tools
    • Base
    • Java
    • Legacy Software Support
    • System Tools
    • X Window System


In addition to the above packages, select any additional packages you wish to install for this node keeping in mind to NOT de-select any of the "default" RPM packages . After selecting the packages to install click [Next] to continue.

About to Install
This screen is basically a confirmation screen. Click [Next] to start the installation. If you are installing Oracle Enterprise Linux using CDs, you will be asked to switch CDs during the installation process depending on which packages you selected.

Congratulations
And that's it. You have successfully installed Oracle Enterprise Linux on the first node (racnode1). The installer will eject the CD/DVD from the CD-ROM drive. Take out the CD/DVD and click [Reboot] to reboot the system.

Post Installation Wizard Welcome Screen
When the system boots into Oracle Enterprise Linux for the first time, it will prompt you with another Welcome screen for the "Post Installation Wizard". The post installation wizard allows you to make final O/S configuration settings. On the "Welcome" screen, click [Forward] to continue.

License Agreement
Read through the license agreement. Choose "Yes, I agree to the License Agreement" and click [Forward] to continue.

Firewall
On this screen, make sure to select the [Disabled] option and click [Forward] to continue.

You will be prompted with a warning dialog about not setting the firewall. When this occurs, click [Yes] to continue.

SELinux
On the SELinux screen, choose the [Disabled] option and click [Forward] to continue.

You will be prompted with a warning dialog warning that changing the SELinux setting will require rebooting the system so the entire file system can be relabeled. When this occurs, click [Yes] to acknowledge a reboot of the system will occur after firstboot (Post Installation Wizard) is completed.

Kdump
Accept the default setting on the Kdump screen (disabled) and click [Forward] to continue.

Date and Time Settings
Adjust the date and time settings if necessary and click [Forward] to continue.

Create User
Create any additional (non-oracle) operating system user accounts if desired and click [Forward] to continue. For the purpose of this article, I will not be creating any additional operating system accounts. I will be creating the "grid" and "oracle" user accounts later in this guide.

If you chose not to define any additional operating system user accounts, click [Continue] to acknowledge the warning dialog.

Sound Card
This screen will only appear if the wizard detects a sound card. On the sound card screen click [Forward] to continue.

Additional CDs
On the "Additional CDs" screen click [Finish] to continue.

Reboot System
Given we changed the SELinux option (to disabled), we are prompted to reboot the system. Click [OK] to reboot the system for normal use.

Login Screen
After rebooting the machine, you are presented with the login screen. Log in using the "root" user account and the password you provided during the installation.

Perform the same installation on the second node
After completing the Linux installation on the first node, repeat the above steps for the second node ( racnode2). When configuring the machine name and networking, ensure to configure the proper values. For my installation, this is what I configured for racnode2:

First, make sure that each of the network devices are checked to [Active on boot]. The installer may choose to not activate eth1.

Second, [Edit] both eth0 and eth1 as follows. Verify that the option "Enable IPv4 support" is selected. Click off the option to use "Dynamic IP configuration (DHCP)" by selecting the "Manual configuration" radio button and configure a static IP address and Netmask for your environment. Click off the option to "Enable IPv6 support". You may choose to use different IP addresses for both eth0 and eth1 that I have documented in this guide and that is OK. Put eth1 (the interconnect) on a different subnet than eth0 (the public network):

eth0:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to use [Dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.1.152
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

eth1:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to use [Dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.2.152
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

Continue by setting your hostname manually. I used " racnode2" for the second node. Finish this dialog off by supplying your gateway and DNS servers.

 


7. Install Required Linux Packages for Oracle RAC

Install the following required Linux packages on both Oracle RAC nodes in the cluster.

After installing Enterprise Linux, the next step is to verify and install all packages (RPMs) required by both Oracle Clusterware and Oracle RAC. The Oracle Universal Installer (OUI) performs checks on your machine during installation to verify that it meets the appropriate operating system package requirements. To ensure that these checks complete successfully, verify the software requirements documented in this section before starting the Oracle installs.

Although many of the required packages for Oracle were installed during the Enterprise Linux installation, several will be missing either because they were considered optional within the package group or simply didn't exist in any package group!

The packages listed in this section (or later versions) are required for Oracle grid infrastructure 11g Release 2 and Oracle RAC 11g Release 2 running on the Enterprise Linux 5 platform.

 

32-bit (x86) Installations

 

  • binutils-2.17.50.0.6
  • compat-libstdc++-33-3.2.3
  • elfutils-libelf-0.125
  • elfutils-libelf-devel-0.125
  • elfutils-libelf-devel-static-0.125
  • gcc-4.1.2
  • gcc-c++-4.1.2
  • glibc-2.5-24
  • glibc-common-2.5
  • glibc-devel-2.52
  • glibc-headers-2.5
  • kernel-headers-2.6.18
  • ksh-20060214
  • libaio-0.3.106
  • libaio-devel-0.3.106
  • libgcc-4.1.2
  • libgomp-4.1.2
  • libstdc++-4.1.2
  • libstdc++-devel-4.1.2
  • make-3.81
  • sysstat-7.0.2
  • unixODBC-2.2.11
  • unixODBC-devel-2.2.11


Each of the packages listed above can be found on CD #1, CD #2, and CD #3 on the Enterprise Linux 5 - (x86) CDs. While it is possible to query each individual package to determine which ones are missing and need to be installed, an easier method is to run the rpm -Uvh PackageName command from the five CDs as follows. For packages that already exist and are up to date, the RPM command will simply ignore the install and print a warning message to the console that the package is already installed.

#  
                         From Enterprise Linux 5.4 (x86)- [CD #1]
mkdir -p /media/cdrom
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh binutils-2.*
rpm -Uvh elfutils-libelf-0.*
rpm -Uvh glibc-2.*
rpm -Uvh glibc-common-2.*
rpm -Uvh kernel-headers-2.*
rpm -Uvh ksh-2*
rpm -Uvh libaio-0.*
rpm -Uvh libgcc-4.*
rpm -Uvh libstdc++-4.*
rpm -Uvh make-3.*
cd /
eject


#  
                         From Enterprise Linux 5.4 (x86) - [CD #2]
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh elfutils-libelf-devel-*
rpm -Uvh gcc-4.*
rpm -Uvh gcc-c++-4.*
rpm -Uvh glibc-devel-2.*
rpm -Uvh glibc-headers-2.*
rpm -Uvh libgomp-4.*
rpm -Uvh libstdc++-devel-4.*
rpm -Uvh unixODBC-2.*
cd /
eject


#  
                         From Enterprise Linux 5.4 (x86) - [CD #3]
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh compat-libstdc++-33*
rpm -Uvh libaio-devel-0.*
rpm -Uvh sysstat-7.*
rpm -Uvh unixODBC-devel-2.*
cd /
eject
                      

 

64-bit (x86_64) Installations

 

  • binutils-2.17.50.0.6
  • compat-libstdc++-33-3.2.3
  • compat-libstdc++-33-3.2.3 (32 bit)
  • elfutils-libelf-0.125
  • elfutils-libelf-devel-0.125
  • elfutils-libelf-devel-static-0.125
  • gcc-4.1.2
  • gcc-c++-4.1.2
  • glibc-2.5-24
  • glibc-2.5-24 (32 bit)
  • glibc-common-2.5
  • glibc-devel-2.5
  • glibc-devel-2.5 (32 bit)
  • glibc-headers-2.5
  • ksh-20060214
  • libaio-0.3.106
  • libaio-0.3.106 (32 bit)
  • libaio-devel-0.3.106
  • libaio-devel-0.3.106 (32 bit)
  • libgcc-4.1.2
  • libgcc-4.1.2 (32 bit)
  • libstdc++-4.1.2
  • libstdc++-4.1.2 (32 bit)
  • libstdc++-devel 4.1.2
  • make-3.81
  • sysstat-7.0.2
  • unixODBC-2.2.11
  • unixODBC-2.2.11 (32 bit)
  • unixODBC-devel-2.2.11
  • unixODBC-devel-2.2.11 (32 bit)


Each of the packages listed above can be found on CD #1, CD #2, CD #3, and CD #4 on the Enterprise Linux 5 - (x86_64) CDs. While it is possible to query each individual package to determine which ones are missing and need to be installed, an easier method is to run the rpm -Uvh PackageName command from the six CDs as follows. For packages that already exist and are up to date, the RPM command will simply ignore the install and print a warning message to the console that the package is already installed.

#  
                         From Enterprise Linux 5.4 (x86_64)- [CD #1]
mkdir -p /media/cdrom
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh binutils-2.*
rpm -Uvh elfutils-libelf-0.*
rpm -Uvh glibc-2.*
rpm -Uvh glibc-common-2.*
rpm -Uvh ksh-2*
rpm -Uvh libaio-0.*
rpm -Uvh libgcc-4.*
rpm -Uvh libstdc++-4.*
rpm -Uvh make-3.*
cd /
eject


#  
                         From Enterprise Linux 5.4 (x86_64) - [CD #2]
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh elfutils-libelf-devel-*
rpm -Uvh gcc-4.*
rpm -Uvh gcc-c++-4.*
rpm -Uvh glibc-devel-2.*
rpm -Uvh glibc-headers-2.*
rpm -Uvh libstdc++-devel-4.*
rpm -Uvh unixODBC-2.*
cd /
eject


#  
                         From Enterprise Linux 5.4 (x86_64) - [CD #3]
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh compat-libstdc++-33*
rpm -Uvh libaio-devel-0.*
rpm -Uvh unixODBC-devel-2.*
cd /
eject


#  
                         From Enterprise Linux 5.4 (x86_64) - [CD #4]
mount -r /dev/cdrom /media/cdrom
cd /media/cdrom/Server
rpm -Uvh sysstat-7.*
cd /
eject
                      

 


8. Network Configuration

Perform the following network configuration on both Oracle RAC nodes in the cluster.

Although we configured several of the network settings during the Linux installation, it is important to not skip this section as it contains critical steps to check that you have the networking hardware and Internet Protocol (IP) addresses required for an Oracle grid infrastructure for a cluster installation.

Network Hardware Requirements

The following is a list of hardware requirements for network configuration:

 

  • Each Oracle RAC node must have at least two network adapters or network interface cards (NICs): one for the public network interface, and one for the private network interface (the interconnect). To use multiple NICs for the public network or for the private network, Oracle recommends that you use NIC bonding. Use separate bonding for the public and private networks (i.e. bond0 for the public network and bond1 for the private network), because during installation each interface is defined as a public or private interface. NIC bonding is not covered in this article.
  •  

  • The public interface names associated with the network adapters for each network must be the same on all nodes, and the private interface names associated with the network adaptors should be the same on all nodes.

     

    For example, with our two-node cluster, you cannot configure network adapters on racnode1 with eth0 as the public interface, but on racnode2 have eth1 as the public interface. Public interface names must be the same, so you must configure eth0 as public on both nodes. You should configure the private interfaces on the same network adapters as well. If eth1 is the private interface for racnode1, then eth1 must be the private interface for racnode2.
  •  

  • For the public network, each network adapter must support TCP/IP.
  •  

  • For the private network, the interconnect must support the user datagram protocol (UDP) using high-speed network adapters and switches that support TCP/IP (minimum requirement 1 Gigabit Ethernet).

     

    UDP is the default interconnect protocol for Oracle RAC, and TCP is the interconnect protocol for Oracle Clusterware. You must use a switch for the interconnect. Oracle recommends that you use a dedicated switch.

     

    Oracle does not support token-rings or crossover cables for the interconnect.
  •  

  • For the private network, the endpoints of all designated interconnect interfaces must be completely reachable on the network. There should be no node that is not connected to every private network interface. You can test if an interconnect interface is reachable using ping.
  •  

  • During installation of Oracle grid infrastructure, you are asked to identify the planned use for each network interface that OUI detects on your cluster node. You must identify each interface as a public interface, a private interface, or not used and you must use the same private interfaces for both Oracle Clusterware and Oracle RAC.

     

    You can bond separate interfaces to a common interface to provide redundancy, in case of a NIC failure, but Oracle recommends that you do not create separate interfaces for Oracle Clusterware and Oracle RAC. If you use more than one NIC for the private interconnect, then Oracle recommends that you use NIC bonding. Note that multiple private interfaces provide load balancing but not failover, unless bonded.

     

    Starting with Oracle Clusterware 11g Release 2, you no longer need to provide a private name or IP address for the interconnect. IP addresses on the subnet you identify as private are assigned as private IP addresses for cluster member nodes. You do not need to configure these addresses manually in a hosts directory. If you want name resolution for the interconnect, then you can configure private IP names in the hosts file or the DNS. However, Oracle Clusterware assigns interconnect addresses on the interface defined during installation as the private interface ( eth1, for example), and to the subnet used for the private subnet. In practice, and for the purpose of this guide, I will continue to include a private name and IP address on each node for the RAC interconnect. It provides self-documentation and a set of end-points on the private network I can use for troubleshooting purposes:
    192.168.2.151   racnode1-priv
    192.168.2.152   racnode2-priv
    
  •  

  • In a production environment that uses iSCSI for network storage, it is highly recommended to configure a redundant third network interface ( eth2, for example) for that storage traffic using a TCP/IP offload Engine (TOE) card. For the sake of brevity, this article will configure the iSCSI network storage traffic on the same network as the RAC private interconnect ( eth1). Combining the iSCSI storage traffic and cache fusion traffic for Oracle RAC on the same network interface works great for an inexpensive test system but should never be considered for production.

     

    The basic idea of a TOE is to offload the processing of TCP/IP protocols from the host processor to the hardware on the adapter or in the system. A TOE if often embedded in a network interface card (NIC) or a host bus adapter (HBA) and used to reduce the amount of TCP/IP processing handled by the CPU and server I/O subsystem and improve overall performance.


Assigning IP Address

Recall that each node requires at least two network interfaces configured — one for the private IP address and one for the public IP address. Prior to Oracle Clusterware 11g Release 2, all IP addresses needed to be manually assigned by the network administrator using static IP addresses — never to use DHCP. This would include the public IP address for the node, the RAC interconnect, virtual IP address (VIP), and new to 11g Release 2, the Single Client Access Name (SCAN) IP address(s). In fact, in all of my previous articles, I would emphatically state that DHCP should never be used to assign any of these IP addresses. Well, in 11g Release 2, you now have two options that can used to assign IP addresses to each Oracle RAC node — Grid Naming Service (GNS) which uses DHCP or the traditional method of manually assigning static IP addresses using DNS.

Grid Naming Service (GNS)

Starting with Oracle Clusterware 11g Release 2, a second method for assigning IP addresses named Grid Naming Service (GNS) was introduced that allows all private interconnect addresses, as well as most of the VIP addresses to be assigned using DHCP. GNS and DHCP are key elements to Oracle's new Grid Plug and Play (GPnP) feature that, as Oracle states, eliminates per-node configuration data and the need for explicit add and delete nodes steps. GNS enables a dynamic grid infrastructure through the self-management of the network requirements for the cluster. While configuring IP addresses using GNS certainly has its benefits and offers more flexibility over manually defining static IP addresses, it does come at the cost of complexity and requires components not defined in this guide on building an inexpensive Oracle RAC. For example, activating GNS in a cluster requires a DHCP server on the public network which I felt was out of the scope of this article.

To learn more about the benefits and how to configure GNS, please see Oracle Grid Infrastructure Installation Guide 11g Release 2 (11.2) for Linux .

Manually Assigning Static IP Address - (The DNS Method)

If you choose not to use GNS, manually defining static IP addresses is still available with Oracle Clusterware 11g Release 2 and will be the method used in this article to assign all required Oracle Clusterware networking components (public IP address for the node, RAC interconnect, virtual IP address, and SCAN).

Notice that the title of this section includes the phrase "The DNS Method". Oracle recommends that static IP addresses be manually configured in a domain name server (DNS) before starting the Oracle grid infrastructure installation. However, when building an inexpensive Oracle RAC, it is not always possible you will have access to a DNS server. Previous to 11g Release 2, this would not present a huge obstacle as it was possible to define each IP address in the host file ( /etc/hosts) on all nodes without the use of DNS. This would include public IP address for the node, the RAC interconnect, and the virtual IP address (VIP).

Things, however, change a bit in Oracle grid infrastructure 11g Release 2.

Let's start with the RAC private interconnect. It is no longer a requirement to provide a private name or IP address for the interconnect during the Oracle grid infrastructure install (i.e. racnode1-priv or racnode2-priv). Oracle Clusterware now assigns interconnect addresses on the interface defined during installation as the private interface ( eth1, for example), and to the subnet used for the private subnet, which for this article is 192.168.2.0. If you want name resolution for the interconnect, then you can configure private IP names in the hosts file or the DNS. In practice, and for the purpose of this guide, I will continue to include a private name and IP address on each node for the RAC interconnect. It provides self-documentation and a set of end-points on the private network I can use for troubleshooting purposes:

192.168.2.151   racnode1-priv
192.168.2.152   racnode2-priv


The public IP address for the node and the virtual IP address (VIP) remain the same in 11g Release 2. Oracle recommends defining the name and IP address for each to be resolved through DNS and included in the hosts file for each node. With the current release of Oracle grid infrastructure and previous releases, Oracle Clusterware has no problem resolving the public IP address for the node and the VIP using only a hosts file:

192.168.1.151   racnode1
192.168.1.251   racnode1-vip
192.168.1.152   racnode2
192.168.1.252   racnode2-vip


The Single Client Access Name (SCAN) virtual IP is new to 11g Release 2 and seems to be the one causing the most discussion! The SCAN must be configured in GNS or DNS for Round Robin resolution to three addresses (recommended) or at least one address. If you choose not to use GNS, then Oracle states the SCAN must be resolved through DNS and not through the hosts file. If the SCAN cannot be resolved through DNS (or GNS), the Cluster Verification Utility check will fail during the Oracle grid infrastructure installation. If you do not have access to a DNS, I provide an easy workaround in the section Configuring SCAN without DNS. The workaround involves modifying the nslookup utility and should be performed before installing Oracle grid infrastructure.

Single Client Access Name (SCAN) for the Cluster

If you have ever been tasked with extending an Oracle RAC cluster by adding a new node (or shrinking a RAC cluster by removing a node), then you know the pain of going through a list of all clients and updating their SQL*Net or JDBC configuration to reflect the new or deleted node! To address this problem, Oracle 11g Release 2 introduced a new feature known as Single Client Access Name or SCAN for short. SCAN is a new feature that provides a single host name for clients to access an Oracle Database running in a cluster. Clients using SCAN do not need to change their TNS configuration if you add or remove nodes in the cluster. The SCAN resource and its associated IP address(s) provide a stable name for clients to use for connections, independent of the nodes that make up the cluster. You will be asked to provide the host name and up to three IP addresses to be used for the SCAN resource during the interview phase of the Oracle grid infrastructure installation. For high availability and scalability, Oracle recommends that you configure the SCAN name so that it resolves to three IP addresses. At a minimum, the SCAN must resolve to at least one address.

The SCAN virtual IP name is similar to the names used for a node's virtual IP addresses, such as racnode1-vip. However, unlike a virtual IP, the SCAN is associated with the entire cluster, rather than an individual node, and can be associated with multiple IP addresses, not just one address. Note that SCAN addresses, virtual IP addresses, and public IP addresses must all be on the same subnet.

The SCAN should be configured so that it is resolvable either by using Grid Naming Service (GNS) within the cluster, or by using Domain Name Service (DNS) resolution.

In this article, I will configure SCAN to resolve to only one, manually configured static IP address using the DNS method ( but not actually defining it in DNS):

192.168.1.187   racnode-cluster-scan


Configuring Public and Private Network

In our two node example, we need to configure the network on both Oracle RAC nodes for access to the public network as well as their private interconnect.

The easiest way to configure network settings in Enterprise Linux is with the program "Network Configuration". Network Configuration is a GUI application that can be started from the command-line as the "root" user account as follows:

[root@racnode1 ~]#  
                         /usr/bin/system-config-network &
                      

Using the Network Configuration application, you need to configure both NIC devices as well as the /etc/hosts file. Both of these tasks can be completed using the Network Configuration GUI. Notice that the /etc/hosts settings are the same for both nodes and that I removed any entry that has to do with IPv6. For example:

                           
::1             localhost6.localdomain6 localhost6
                        

Our example Oracle RAC configuration will use the following network settings:

Oracle RAC Node 1 - (racnode1)
Device IP Address Subnet Gateway Purpose
eth0 192.168.1.151 255.255.255.0 192.168.1.1 Connects racnode1 to the public network
eth1 192.168.2.151 255.255.255.0   Connects racnode1 (interconnect) to racnode2 (racnode2-priv)
/etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.

127.0.0.1        localhost.localdomain   localhost

                                 
# Public Network - (eth0)
192.168.1.151    racnode1
192.168.1.152    racnode2

# Private Interconnect - (eth1)
192.168.2.151    racnode1-priv
192.168.2.152    racnode2-priv

# Public Virtual IP (VIP) addresses - (eth0:1)
192.168.1.251    racnode1-vip
192.168.1.252    racnode2-vip

# Single Client Access Name (SCAN)
192.168.1.187    racnode-cluster-scan

# Private Storage Network for Openfiler - (eth1)
192.168.1.195    openfiler1
192.168.2.195    openfiler1-priv

# Miscellaneous Nodes
192.168.1.1      router
192.168.1.105    packmule
192.168.1.106    melody
192.168.1.121    domo
192.168.1.122    switch1
192.168.1.125    oemprod
192.168.1.245    accesspoint
                              

 

Oracle RAC Node 2 - (racnode2)
Device IP Address Subnet Gateway Purpose
eth0 192.168.1.152 255.255.255.0 192.168.1.1 Connects racnode2 to the public network
eth1 192.168.2.152 255.255.255.0   Connects racnode2 (interconnect) to racnode1 (racnode1-priv)
/etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.

127.0.0.1        localhost.localdomain   localhost

                                 
# Public Network - (eth0)
192.168.1.151    racnode1
192.168.1.152    racnode2

# Private Interconnect - (eth1)
192.168.2.151    racnode1-priv
192.168.2.152    racnode2-priv

# Public Virtual IP (VIP) addresses - (eth0:1)
192.168.1.251    racnode1-vip
192.168.1.252    racnode2-vip

# Single Client Access Name (SCAN)
192.168.1.187    racnode-cluster-scan

# Private Storage Network for Openfiler - (eth1)
192.168.1.195    openfiler1
192.168.2.195    openfiler1-priv

# Miscellaneous Nodes
192.168.1.1      router
192.168.1.105    packmule
192.168.1.106    melody
192.168.1.121    domo
192.168.1.122    switch1
192.168.1.125    oemprod
192.168.1.245    accesspoint
                              

In the screen shots below, only Oracle RAC Node 1 (racnode1) is shown. Be sure to make all the proper network settings to both Oracle RAC nodes.

Figure 2: Network Configuration Screen, Node 1 (racnode1)


Figure 3: Ethernet Device Screen, eth0 (racnode1)


Figure 4: Ethernet Device Screen, eth1 (racnode1)


Figure 5: Network Configuration Screen, /etc/hosts (racnode1)


Once the network is configured, you can use the ifconfig command to verify everything is working. The following example is from racnode1:

[root@racnode1 ~]#  
                         /sbin/ifconfig -a

eth0      Link encap:Ethernet  HWaddr 00:14:6C:76:5C:71
          inet addr:192.168.1.151  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::214:6cff:fe76:5c71/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:759780 errors:0 dropped:0 overruns:0 frame:0
          TX packets:771948 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:672708275 (641.5 MiB)  TX bytes:727861314 (694.1 MiB)
          Interrupt:177 Base address:0xcf00

eth1      Link encap:Ethernet  HWaddr 00:0E:0C:64:D1:E5
          inet addr:192.168.2.151  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::20e:cff:fe64:d1e5/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:120 errors:0 dropped:0 overruns:0 frame:0
          TX packets:48 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:24544 (23.9 KiB)  TX bytes:8634 (8.4 KiB)
          Base address:0xddc0 Memory:fe9c0000-fe9e0000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:3191 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3191 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:4296868 (4.0 MiB)  TX bytes:4296868 (4.0 MiB)

sit0      Link encap:IPv6-in-IPv4
          NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)
                      

Confirm the RAC Node Name is Not Listed in Loopback Address

Ensure that the node names ( racnode1 or racnode2) are not included for the loopback address in the /etc/hosts file. If the machine name is listed in the in the loopback address entry as below:

127.0.0.1  
                          
                              racnode1
                           localhost.localdomain localhost
                        

it will need to be removed as shown below:

127.0.0.1 localhost.localdomain localhost

If the RAC node name is listed for the loopback address, you will receive the following error during the RAC installation:

                           
ORA-00603: ORACLE server session terminated by fatal error
                        
or
                           
ORA-29702: error occurred in Cluster Group Service operation
                        

Check and turn off UDP ICMP rejections

During the Linux installation process, I indicated to not configure the firewall option. By default the option to configure a firewall is selected by the installer. This has burned me several times so I like to do a double-check that the firewall option is not configured and to ensure udp ICMP filtering is turned off.

If UDP ICMP is blocked or rejected by the firewall, the Oracle Clusterware software will crash after several minutes of running. When the Oracle Clusterware process fails, you will have something similar to the following in the <machine_name>_evmocr.log file:

                         
08/29/2005 22:17:19
oac_init:2: Could not connect to server, clsc retcode = 9
                          

08/29/2005 22:17:19
a_init:12!: Client init unsuccessful : [32]
ibctx:1:ERROR: INVALID FORMAT
proprinit:problem reading the bootblock or superbloc 22
                        
                      

When experiencing this type of error, the solution is to remove the UDP ICMP (iptables) rejection rule - or to simply have the firewall option turned off. The Oracle Clusterware software will then start to operate normally and not crash. The following commands should be executed as the root user account:

  1.  

  2. Check to ensure that the firewall option is turned off. If the firewall option is stopped (like it is in my example below) you do not have to proceed with the following steps.
    [root@racnode1 ~]#  
                                 /etc/rc.d/init.d/iptables status
    Firewall is stopped.
                              

     

  3. If the firewall option is operating you will need to first manually disable UDP ICMP rejections:
    [root@racnode1 ~]#  
                                 /etc/rc.d/init.d/iptables stop
    Flushing firewall rules: [  
                                
    OK ]
    Setting chains to policy ACCEPT: filter [  
                                
    OK ]
    Unloading iptables modules: [  
                                
    OK ]
                              

     

  4. Then, to turn UDP ICMP rejections off for next server reboot (which should always be turned off):
    [root@racnode1 ~]#  
                                 chkconfig iptables off
                              

 


9. Cluster Time Synchronization Service

Perform the following Cluster Time Synchronization Service configuration on both Oracle RAC nodes in the cluster.

Oracle Clusterware 11g Release 2 and later requires time synchronization across all nodes within a cluster where Oracle RAC is deployed. Oracle provide two options for time synchronization: an operating system configured network time protocol (NTP), or the new Oracle Cluster Time Synchronization Service (CTSS). Oracle Cluster Time Synchronization Service (ctssd) is designed for organizations whose Oracle RAC databases are unable to access NTP services.

Configuring NTP is outside the scope of this article and will therefore rely on the Cluster Time Synchronization Service as the network time protocol.

Configure Cluster Time Synchronization Service - (CTSS)

If you want to use Cluster Time Synchronization Service to provide synchronization service in the cluster, then de-configure and de-install the Network Time Protocol (NTP).

To deactivate the NTP service, you must stop the existing ntpd service, disable it from the initialization sequences and remove the ntp.conf file. To complete these steps on Oracle Enterprise Linux, run the following commands as the root user on both Oracle RAC nodes:

[root@racnode1 ~]#  
                         /sbin/service ntpd stop
[root@racnode1 ~]#  
                         chkconfig ntpd off
[root@racnode1 ~]#  
                         mv /etc/ntp.conf /etc/ntp.conf.original
                      

Also remove the following file:

[root@racnode1 ~]#  
                         rm /var/run/ntpd.pid
                      

This file maintains the pid for the NTP daemon.

When the installer finds that the NTP protocol is not active, the Cluster Time Synchronization Service is automatically installed in active mode and synchronizes the time across the nodes. If NTP is found configured, then the Cluster Time Synchronization Service is started in observer mode, and no active time synchronization is performed by Oracle Clusterware within the cluster.

To confirm that ctssd is active after installation, enter the following command as the Grid installation owner ( grid):

[grid@racnode1 ~]$  
                         crsctl check ctss
CRS-4701: The Cluster Time Synchronization Service is in Active mode.
CRS-4702: Offset (in msec): 0
                      

Configure Network Time Protocol - (only if not using CTSS as documented above)

Note: Please note that this guide will use Cluster Time Synchronization Service for time synchronization across both Oracle RAC nodes in the cluster. This section is provided for documentation purposes only and can be used by organizations already setup to use NTP within their domain.

If you are using NTP, and you prefer to continue using it instead of Cluster Time Synchronization Service, then you need to modify the NTP initialization file to set the -x flag, which prevents time from being adjusted backward. Restart the network time protocol daemon after you complete this task.

To do this on Oracle Enterprise Linux, Red Hat Linux, and Asianux systems, edit the /etc/sysconfig/ntpd file to add the -x flag, as in the following example:

# Drop root to id 'ntp:ntp' by default.
OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid"
# Set to 'yes' to sync hw clock after successful ntpdate
SYNC_HWCLOCK=no
# Additional options for ntpdate
NTPDATE_OPTIONS=""

Then, restart the NTP service.

#  
                         /sbin/service ntp restart
                      

On SUSE systems, modify the configuration file /etc/sysconfig/ntp with the following settings:

NTPD_OPTIONS="-x -u ntp"

Restart the daemon using the following command:

#  
                         service ntp restart
                      

 


10. Install Openfiler

Perform the following installation on the network storage server (openfiler1).

With the network configured on both Oracle RAC nodes, the next step is to install the Openfiler software to the network storage server ( openfiler1). Later in this article, the network storage server will be configured as an iSCSI storage device for all Oracle Clusterware and Oracle RAC shared storage requirements.

Powered by rPath Linux, Openfiler is a free browser-based network storage management utility that delivers file-based Network Attached Storage (NAS) and block-based Storage Area Networking (SAN) in a single framework. The entire software stack interfaces with open source applications such as Apache, Samba, LVM2, ext3, Linux NFS and iSCSI Enterprise Target. Openfiler combines these ubiquitous technologies into a small, easy to manage solution fronted by a powerful web-based management interface.

Openfiler supports CIFS, NFS, HTTP/DAV, FTP, however, we will only be making use of its iSCSI capabilities to implement an inexpensive SAN for the shared storage components required by Oracle RAC 11g. The operating system and Openfiler application will be installed on one internal SATA disk. A second internal 73GB 15K SCSI hard disk will be configured as a single "Volume Group" that will be used for all shared disk storage requirements. The Openfiler server will be configured to use this volume group for iSCSI based storage and will be used in our Oracle RAC 11g configuration to store the shared files required by Oracle Clusterware and the Oracle RAC database.

Please be aware that any type of hard disk (internal or external) should work for database storage as long as it can be recognized by the network storage server (Openfiler) and has adequate space. For example, I could have made an extra partition on the 500GB internal SATA disk for the iSCSI target, but decided to make use of the faster SCSI disk for this example.

To learn more about Openfiler, please visit their website at http://www.openfiler.com/

Download Openfiler

Use the links below to download Openfiler NAS/SAN Appliance, version 2.3 (Final Release) for either x86 or x86_64 depending on your hardware architecture. This guide uses x86_64. After downloading Openfiler, you will then need to burn the ISO image to CD.

32-bit (x86) Installations

 



64-bit (x86_64) Installations

 



If you are downloading the above ISO file to a MS Windows machine, there are many options for burning these images (ISO files) to a CD. You may already be familiar with and have the proper software to burn images to CD. If you are not familiar with this process and do not have the required software to burn images to CD, here are just two (of many) software packages that can be used:

 



Install Openfiler

This section provides a summary of the screens used to install the Openfiler software. For the purpose of this article, I opted to install Openfiler with all default options. The only manual change required was for configuring the local network settings.

Once the install has completed, the server will reboot to make sure all required components, services and drivers are started and recognized. After the reboot, any external hard drives (if connected) will be discovered by the Openfiler server.

For more detailed installation instructions, please visit http://www.openfiler.com/learn/. I would suggest, however, that the instructions I have provided below be used for this Oracle RAC 11g configuration.

Before installing the Openfiler software to the network storage server, you should have both NIC interfaces (cards) installed and any external hard drives connected and turned on (if you will be using external hard drives).

After downloading and burning the Openfiler ISO image (ISO file) to CD, insert the CD into the network storage server ( openfiler1 in this example), power it on, and answer the installation screen prompts as noted below.

Boot Screen
The first screen is the Openfiler boot screen. At the boot: prompt, hit [Enter] to start the installation process.

Media Test
When asked to test the CD media, tab over to [Skip] and hit [Enter]. If there were any errors, the media burning software would have warned us. After several seconds, the installer should then detect the video card, monitor, and mouse. The installer then goes into GUI mode.

Welcome to Openfiler NSA
At the welcome screen, click [Next] to continue.

Keyboard Configuration
The next screen prompts you for the Keyboard settings. Make the appropriate selection for your configuration.

Disk Partitioning Setup
The next screen asks whether to perform disk partitioning using "Automatic Partitioning" or "Manual Partitioning with Disk Druid". Although the official Openfiler documentation suggests to use Manual Partitioning, I opted to use "Automatic Partitioning" given the simplicity of my example configuration.

Select [Automatically partition] and click [Next] continue.

Automatic Partitioning
If there were a previous installation of Linux on this machine, the next screen will ask if you want to "remove" or "keep" old partitions. Select the option to [Remove all partitions on this system]. For my example configuration, I selected ONLY the 500GB SATA internal hard drive [sda] for the operating system and Openfiler application installation. I de-selected the 73GB SCSI internal hard drive since this disk will be used exclusively in the next section to create a single "Volume Group" that will be used for all iSCSI based shared disk storage requirements for Oracle Clusterware and Oracle RAC.

I also keep the checkbox [Review (and modify if needed) the partitions created] selected. Click [Next] to continue.

You will then be prompted with a dialog window asking if you really want to remove all partitions. Click [Yes] to acknowledge this warning.

Partitioning
The installer will then allow you to view (and modify if needed) the disk partitions it automatically chose for hard disks selected in the previous screen. In almost all cases, the installer will choose 100MB for /boot, an adequate amount of swap, and the rest going to the root ( /) partition for that disk (or disks). In this example, I am satisfied with the installers recommended partitioning for /dev/sda.

The installer will also show any other internal hard disks it discovered. For my example configuration, the installer found the 73GB SCSI internal hard drive as /dev/sdb. For now, I will "Delete" any and all partitions on this drive (there was only one, /dev/sdb1). In the next section, I will create the required partition for this particular hard disk.

Network Configuration
I made sure to install both NIC interfaces (cards) in the network storage server before starting the Openfiler installation. This screen should have successfully detected each of the network devices.

First, make sure that each of the network devices are checked to [Active on boot]. The installer may choose to not activate eth1 by default.

Second, [Edit] both eth0 and eth1 as follows. You may choose to use different IP addresses for both eth0 and eth1 and that is OK. You must, however, configure eth1 (the storage network) to be on the same subnet you configured for eth1 on racnode1 and racnode2:

eth0:
- Check off the option to [Configure using DHCP]
- Leave the [Activate on boot] checked
- IP Address: 192.168.1.195
- Netmask: 255.255.255.0

eth1:
- Check off the option to [Configure using DHCP]
- Leave the [Activate on boot] checked
- IP Address: 192.168.2.195
- Netmask: 255.255.255.0

Continue by setting your hostname manually. I used a hostname of " openfiler1". Finish this dialog off by supplying your gateway and DNS servers.



Time Zone Selection
The next screen allows you to configure your time zone information. Make the appropriate selection for your location.

Set Root Password
Select a root password and click [Next] to continue.

About to Install
This screen is basically a confirmation screen. Click [Next] to start the installation.

Congratulations
And that's it. You have successfully installed Openfiler on the network storage server. The installer will eject the CD from the CD-ROM drive. Take out the CD and click [Reboot] to reboot the system.

If everything was successful after the reboot, you should now be presented with a text login screen and the URL to use for administering the Openfiler server.

Modify /etc/hosts File on Openfiler Server
Although not mandatory, I typically copy the contents of the /etc/hosts file from one of the Oracle RAC nodes to the new Openfiler server. This allows convenient name resolution when testing the network for the cluster.

 


11. Configure iSCSI Volumes using Openfiler

Perform the following configuration tasks on the network storage server (openfiler1).

Openfiler administration is performed using the Openfiler Storage Control Center — a browser based tool over an https connection on port 446. For example:

                         
https://openfiler1.idevelopment.info:446/
                      

From the Openfiler Storage Control Center home page, log in as an administrator. The default administration login credentials for Openfiler are:

 

  • Username: openfiler
  • Password: password


The first page the administrator sees is the [Status] / [System Information] screen.

To use Openfiler as an iSCSI storage server, we have to perform six major tasks; set up iSCSI services, configure network access, identify and partition the physical storage, create a new volume group, create all logical volumes, and finally, create new iSCSI targets for each of the logical volumes.

Services

To control services, we use the Openfiler Storage Control Center and navigate to [Services] / [Manage Services]:



Figure 6: Enable iSCSI Openfiler Service

To enable the iSCSI service, click on the 'Enable' link under the 'iSCSI target server' service name. After that, the 'iSCSI target server' status should change to ' Enabled '.

The ietd program implements the user level part of iSCSI Enterprise Target software for building an iSCSI storage system on Linux. With the iSCSI target enabled, we should be able to SSH into the Openfiler server and see the iscsi-target service running:

[root@openfiler1 ~]#  
                         service iscsi-target status
ietd (pid 14243) is running...
                      

Network Access Configuration

The next step is to configure network access in Openfiler to identify both Oracle RAC nodes ( racnode1 and racnode2) that will need to access the iSCSI volumes through the storage (private) network. Note that iSCSI logical volumes will be created later on in this section. Also note that this step does not actually grant the appropriate permissions to the iSCSI volumes required by both Oracle RAC nodes. That will be accomplished later in this section by updating the ACL for each new logical volume.

As in the previous section, configuring network access is accomplished using the Openfiler Storage Control Center by navigating to [System] / [Network Setup]. The "Network Access Configuration" section (at the bottom of the page) allows an administrator to setup networks and/or hosts that will be allowed to access resources exported by the Openfiler appliance. For the purpose of this article, we will want to add both Oracle RAC nodes individually rather than allowing the entire 192.168.2.0 network have access to Openfiler resources.

When entering each of the Oracle RAC nodes, note that the 'Name' field is just a logical name used for reference only. As a convention when entering nodes, I simply use the node name defined for that IP address. Next, when entering the actual node in the 'Network/Host' field, always use its IP address even though its host name may already be defined in your /etc/hosts file or DNS. Lastly, when entering actual hosts in our Class C network, use a subnet mask of 255.255.255.255.

It is important to remember that you will be entering the IP address of the private network ( eth1) for each of the RAC nodes in the cluster.

The following image shows the results of adding both Oracle RAC nodes:



Figure 7: Configure Openfiler Network Access for Oracle RAC Nodes

Physical Storage

In this section, we will be creating the three iSCSI volumes to be used as shared storage by both of the Oracle RAC nodes in the cluster. This involves multiple steps that will be performed on the internal 73GB 15K SCSI hard disk connected to the Openfiler server.

Storage devices like internal IDE/SATA/SCSI/SAS disks, storage arrays, external USB drives, external FireWire drives, or ANY other storage can be connected to the Openfiler server and served to the clients. Once these devices are discovered at the OS level, Openfiler Storage Control Center can be used to set up and manage all of that storage.

In our case, we have a 73GB internal SCSI hard drive for our shared storage needs. On the Openfiler server this drive is seen as /dev/sdb (MAXTOR ATLAS15K2_73SCA). To see this and to start the process of creating our iSCSI volumes, navigate to [Volumes] / [Block Devices] from the Openfiler Storage Control Center:



Figure 8: Openfiler Physical Storage - Block Device Management

Partitioning the Physical Disk

The first step we will perform is to create a single primary partition on the /dev/sdb internal hard disk. By clicking on the /dev/sdb link, we are presented with the options to 'Edit' or 'Create' a partition. Since we will be creating a single primary partition that spans the entire disk, most of the options can be left to their default setting where the only modification would be to change the ' Partition Type' from 'Extended partition' to ' Physical volume'. Here are the values I specified to create the primary partition on /dev/sdb:

Mode: Primary
Partition Type: Physical volume
Starting Cylinder: 1
Ending Cylinder: 8924

The size now shows 68.36 GB. To accept that we click on the "Create" button. This results in a new partition ( /dev/sdb1) on our internal hard disk:



Figure 9: Partition the Physical Volume

Volume Group Management

The next step is to create a Volume Group. We will be creating a single volume group named racdbvg that contains the newly created primary partition.

From the Openfiler Storage Control Center, navigate to [Volumes] / [Volume Groups]. There we would see any existing volume groups, or none as in our case. Using the Volume Group Management screen, enter the name of the new volume group ( racdbvg), click on the checkbox in front of /dev/sdb1 to select that partition, and finally click on the 'Add volume group' button. After that we are presented with the list that now shows our newly created volume group named " racdbvg":



Figure 10: New Volume Group Created

Logical Volumes

We can now create the three logical volumes in the newly created volume group ( racdbvg).

From the Openfiler Storage Control Center, navigate to [Volumes] / [Add Volume]. There we will see the newly created volume group ( racdbvg) along with its block storage statistics. Also available at the bottom of this screen is the option to create a new volume in the selected volume group - (Create a volume in "racdbvg"). Use this screen to create the following three logical (iSCSI) volumes. After creating each logical volume, the application will point you to the "Manage Volumes" screen. You will then need to click back to the "Add Volume" tab to create the next logical volume until all three iSCSI volumes are created:

 

iSCSI / Logical Volumes
Volume Name Volume Description Required Space (MB) Filesystem Type
racdb-crs1 racdb - ASM CRS Volume 1 2,208 iSCSI
racdb-data1 racdb - ASM Data Volume 1 33,888 iSCSI
racdb-fra1 racdb - ASM FRA Volume 1 33,888 iSCSI

In effect we have created three iSCSI disks that can now be presented to iSCSI clients ( racnode1 and racnode2) on the network. The "Manage Volumes" screen should look as follows:



Figure 11: New Logical (iSCSI) Volumes

iSCSI Targets

At this point, we have three iSCSI logical volumes. Before an iSCSI client can have access to them, however, an iSCSI target will need to be created for each of these three volumes. Each iSCSI logical volume will be mapped to a specific iSCSI target and the appropriate network access permissions to that target will be granted to both Oracle RAC nodes. For the purpose of this article, there will be a one-to-one mapping between an iSCSI logical volume and an iSCSI target.

There are three steps involved in creating and configuring an iSCSI target; create a unique Target IQN (basically, the universal name for the new iSCSI target), map one of the iSCSI logical volumes created in the previous section to the newly created iSCSI target, and finally, grant both of the Oracle RAC nodes access to the new iSCSI target. Please note that this process will need to be performed for each of the three iSCSI logical volumes created in the previous section.

For the purpose of this article, the following table lists the new iSCSI target names (the Target IQN) and which iSCSI logical volume it will be mapped to:

iSCSI Target / Logical Volume Mappings
Target IQN iSCSI Volume Name Volume Description
iqn.2006-01.com.openfiler:racdb.crs1 racdb-crs1 racdb - ASM CRS Volume 1
iqn.2006-01.com.openfiler:racdb.data1 racdb-data1 racdb - ASM Data Volume 1
iqn.2006-01.com.openfiler:racdb.fra1 racdb-fra1 racdb - ASM FRA Volume 1

We are now ready to create the three new iSCSI targets - one for each of the iSCSI logical volumes. The example below illustrates the three steps required to create a new iSCSI target by creating the Oracle Clusterware / racdb-crs1 target ( iqn.2006-01.com.openfiler:racdb.crs1). This three step process will need to be repeated for each of the three new iSCSI targets listed in the table above.

Create New Target IQN

From the Openfiler Storage Control Center, navigate to [Volumes] / [iSCSI Targets]. Verify the grey sub-tab "Target Configuration" is selected. This page allows you to create a new iSCSI target. A default value is automatically generated for the name of the new iSCSI target (better known as the "Target IQN"). An example Target IQN is " iqn.2006-01.com.openfiler:tsn.ae4683b67fd3":



Figure 12: Create New iSCSI Target : Default Target IQN

I prefer to replace the last segment of the default Target IQN with something more meaningful. For the first iSCSI target (Oracle Clusterware / racdb-crs1), I will modify the default Target IQN by replacing the string " tsn.ae4683b67fd3" with " racdb.crs1" as shown in Figure 13 below:



Figure 13: Create New iSCSI Target : Replace Default Target IQN

Once you are satisfied with the new Target IQN, click the "Add" button. This will create a new iSCSI target and then bring up a page that allows you to modify a number of settings for the new iSCSI target. For the purpose of this article, none of settings for the new iSCSI target need to be changed.

LUN Mapping

After creating the new iSCSI target, the next step is to map the appropriate iSCSI logical volumes to it. Under the "Target Configuration" sub-tab, verify the correct iSCSI target is selected in the section "Select iSCSI Target". If not, use the pull-down menu to select the correct iSCSI target and hit the "Change" button.

Next, click on the grey sub-tab named "LUN Mapping" (next to "Target Configuration" sub-tab). Locate the appropriate iSCSI logical volume ( /dev/racdbvg/racdb-crs1 in this case) and click the "Map" button. You do not need to change any settings on this page. Your screen should look similar to Figure 14 after clicking the "Map" button for volume /dev/racdbvg/racdb-crs1:



Figure 14: Create New iSCSI Target : Map LUN

Network ACL

Before an iSCSI client can have access to the newly created iSCSI target, it needs to be granted the appropriate permissions. Awhile back, we configured network access in Openfiler for two hosts (the Oracle RAC nodes). These are the two nodes that will need to access the new iSCSI targets through the storage (private) network. We now need to grant both of the Oracle RAC nodes access to the new iSCSI target.

Click on the grey sub-tab named "Network ACL" (next to "LUN Mapping" sub-tab). For the current iSCSI target, change the "Access" for both hosts from 'Deny' to 'Allow' and click the 'Update' button:



Figure 15: Create New iSCSI Target : Update Network ACL

Go back to the Create New Target IQN section and perform these three tasks for the remaining two iSCSI logical volumes while substituting the values found in the " iSCSI Target / Logical Volume Mappings" table .

 


12. Configure iSCSI Volumes on Oracle RAC Nodes

Configure the iSCSI initiator on both Oracle RAC nodes in the cluster. Creating partitions, however, should only be executed on one of nodes in the RAC cluster.

An iSCSI client can be any system (Linux, Unix, MS Windows, Apple Mac, etc.) for which iSCSI support (a driver) is available. In our case, the clients are two Linux servers, racnode1 and racnode2, running Oracle Enterprise Linux 5.4.

In this section we will be configuring the iSCSI software initiator on both of the Oracle RAC nodes. Oracle Enterprise Linux 5.4 includes the Open-iSCSI iSCSI software initiator which can be found in the iscsi-initiator-utils RPM. This is a change from previous versions of Oracle Enterprise Linux (4.x) which included the Linux iscsi-sfnet software driver developed as part of the Linux-iSCSI Project. All iSCSI management tasks like discovery and logins will use the command-line interface iscsiadm which is included with Open-iSCSI.

The iSCSI software initiator will be configured to automatically log in to the network storage server ( openfiler1) and discover the iSCSI volumes created in the previous section. We will then go through the steps of creating persistent local SCSI device names (i.e. /dev/iscsi/crs1) for each of the iSCSI target names discovered using udev. Having a consistent local SCSI device name and which iSCSI target it maps to, helps to differentiate between the three volumes when configuring ASM. Before we can do any of this, however, we must first install the iSCSI initiator software.

Note: This guide makes use of ASMLib 2.0 which is a support library for the Automatic Storage Management (ASM) feature of the Oracle Database. ASMLib will be used to label all iSCSI volumes used in this guide. By default, ASMLib already provides persistent paths and permissions for storage devices used with ASM. This feature eliminates the need for updating udev or devlabel files with storage device paths and permissions. For the purpose of this article and in practice, I still opt to create persistent local SCSI device names for each of the iSCSI target names discovered using udev. This provides a means of self-documentation which helps to quickly identify the name and location of each volume.

Installing the iSCSI (initiator) service

With Oracle Enterprise Linux 5.4, the Open-iSCSI iSCSI software initiator does not get installed by default. The software is included in the iscsi-initiator-utils package which can be found on CD #1. To determine if this package is installed (which in most cases, it will not be), perform the following on both Oracle RAC nodes:

[root@racnode1 ~]#  
                         rpm -qa --queryformat "%{NAME}-%{VERSION}-%{RELEASE} (%{ARCH})\n"| grep iscsi-initiator-utils
                      

If the iscsi-initiator-utils package is not installed, load CD #1 into each of the Oracle RAC nodes and perform the following:

[root@racnode1 ~]#  
                         mount -r /dev/cdrom /media/cdrom
[root@racnode1 ~]#  
                         cd /media/cdrom/Server
[root@racnode1 ~]#  
                         rpm -Uvh iscsi-initiator-utils-*
[root@racnode1 ~]#  
                         cd /
[root@racnode1 ~]#  
                         eject
                      

Verify the iscsi-initiator-utils package is now installed:

[root@racnode1 ~]#  
                         rpm -qa --queryformat "%{NAME}-%{VERSION}-%{RELEASE} (%{ARCH})\n"| grep iscsi-initiator-utils
iscsi-initiator-utils-6.2.0.871-0.10.el5 (x86_64)
                      


Configure the iSCSI (initiator) service

After verifying that the iscsi-initiator-utils package is installed on both Oracle RAC nodes, start the iscsid service and enable it to automatically start when the system boots. We will also configure the iscsi service to automatically start which logs into iSCSI targets needed at system startup.

[root@racnode1 ~]#  
                         service iscsid start
Turning off network shutdown. Starting iSCSI daemon:       [   
                        
OK  ]
                                                           [   
                        
OK  ]

[root@racnode1 ~]#  
                         chkconfig iscsid on
[root@racnode1 ~]#  
                         chkconfig iscsi on
                      

Now that the iSCSI service is started, use the iscsiadm command-line interface to discover all available targets on the network storage server. This should be performed on both Oracle RAC nodes to verify the configuration is functioning properly:

[root@racnode1 ~]#  
                         iscsiadm -m discovery -t sendtargets -p openfiler1-priv
192.168.2.195:3260,1 iqn.2006-01.com.openfiler:racdb.crs1
192.168.2.195:3260,1 iqn.2006-01.com.openfiler:racdb.fra1
192.168.2.195:3260,1 iqn.2006-01.com.openfiler:racdb.data1
                      

Manually Log In to iSCSI Targets

At this point the iSCSI initiator service has been started and each of the Oracle RAC nodes were able to discover the available targets from the network storage server. The next step is to manually log in to each of the available targets which can be done using the iscsiadm command-line interface. This needs to be run on both Oracle RAC nodes. Note that I had to specify the IP address and not the host name of the network storage server ( openfiler1-priv) - I believe this is required given the discovery (above) shows the targets using the IP address.

[root@racnode1 ~]#  
                         iscsiadm -m node -T iqn.2006-01.com.openfiler:racdb.crs1 -p 192.168.2.195 -l
[root@racnode1 ~]#  
                         iscsiadm -m node -T iqn.2006-01.com.openfiler:racdb.data1 -p 192.168.2.195 -l
[root@racnode1 ~]#  
                         iscsiadm -m node -T iqn.2006-01.com.openfiler:racdb.fra1 -p 192.168.2.195 -l
                      

Configure Automatic Log In

The next step is to ensure the client will automatically log in to each of the targets listed above when the machine is booted (or the iSCSI initiator service is started/restarted). As with the manual log in process described above, perform the following on both Oracle RAC nodes:

[root@racnode1 ~]#  
                         iscsiadm -m node -T iqn.2006-01.com.openfiler:racdb.crs1 -p 192.168.2.195 --op update -n node.startup -v automatic
[root@racnode1 ~]#  
                         iscsiadm -m node -T iqn.2006-01.com.openfiler:racdb.data1 -p 192.168.2.195 --op update -n node.startup -v automatic
[root@racnode1 ~]#  
                         iscsiadm -m node -T iqn.2006-01.com.openfiler:racdb.fra1 -p 192.168.2.195 --op update -n node.startup -v automatic
                      

Create Persistent Local SCSI Device Names

In this section, we will go through the steps to create persistent local SCSI device names for each of the iSCSI target names. This will be done using udev. Having a consistent local SCSI device name and which iSCSI target it maps to, helps to differentiate between the three volumes when configuring ASM. Although this is not a strict requirement since we will be using ASMLib 2.0 for all volumes, it provides a means of self-documentation to quickly identify the name and location of each iSCSI volume.

When either of the Oracle RAC nodes boot and the iSCSI initiator service is started, it will automatically log in to each of the targets configured in a random fashion and map them to the next available local SCSI device name. For example, the target iqn.2006-01.com.openfiler:racdb.crs1 may get mapped to /dev/sdb. I can actually determine the current mappings for all targets by looking at the /dev/disk/by-path directory:

[root@racnode1 ~]#  
                         (cd /dev/disk/by-path; ls -l *openfiler* | awk '{FS=" "; print $9 " " $10 " " $11}')
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.crs1-lun-0 -> ../../sdb
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.data1-lun-0 -> ../../sdd
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.fra1-lun-0 -> ../../sdc
                      

Using the output from the above listing, we can establish the following current mappings:

Current iSCSI Target Name to local SCSI Device Name Mappings
iSCSI Target Name SCSI Device Name
iqn.2006-01.com.openfiler:racdb.crs1 /dev/sdb
iqn.2006-01.com.openfiler:racdb.data1 /dev/sdd
iqn.2006-01.com.openfiler:racdb.fra1 /dev/sdc

This mapping, however, may change every time the Oracle RAC node is rebooted. For example, after a reboot it may be determined that the iSCSI target iqn.2006-01.com.openfiler:racdb.crs1 gets mapped to the local SCSI device /dev/sdc. It is therefore impractical to rely on using the local SCSI device name given there is no way to predict the iSCSI target mappings after a reboot.

What we need is a consistent device name we can reference (i.e. /dev/iscsi/crs1) that will always point to the appropriate iSCSI target through reboots. This is where the Dynamic Device Management tool named udev comes in. udev provides a dynamic device directory using symbolic links that point to the actual device using a configurable set of rules. When udev receives a device event (for example, the client logging in to an iSCSI target), it matches its configured rules against the available device attributes provided in sysfs to identify the device. Rules that match may provide additional device information or specify a device node name and multiple symlink names and instruct udev to run additional programs (a SHELL script for example) as part of the device event handling process.

The first step is to create a new rules file. The file will be named /etc/udev/rules.d/55-openiscsi.rules and contain only a single line of name=value pairs used to receive events we are interested in. It will also define a call-out SHELL script ( /etc/udev/scripts/iscsidev.sh) to handle the event.

Create the following rules file /etc/udev/rules.d/55-openiscsi.rules on both Oracle RAC nodes:

..............................................
# /etc/udev/rules.d/55-openiscsi.rules
KERNEL=="sd*", BUS=="scsi", PROGRAM="/etc/udev/scripts/iscsidev.sh %b",SYMLINK+="iscsi/%c/part%n"
..............................................

We now need to create the UNIX SHELL script that will be called when this event is received. Let's first create a separate directory on both Oracle RAC nodes where udev scripts can be stored:

[root@racnode1 ~]#  
                         mkdir -p /etc/udev/scripts
                      

Next, create the UNIX shell script /etc/udev/scripts/iscsidev.sh on both Oracle RAC nodes:

..............................................
#!/bin/sh

# FILE: /etc/udev/scripts/iscsidev.sh

BUS=${1}
HOST=${BUS%%:*}

[ -e /sys/class/iscsi_host ] || exit 1

file="/sys/class/iscsi_host/host${HOST}/device/session*/iscsi_session*/targetname"

target_name=$(cat ${file})

# This is not an open-scsi drive
if [ -z "${target_name}" ]; then
   exit 1
fi

# Check if QNAP drive
check_qnap_target_name=${target_name%%:*}
if [ $check_qnap_target_name = "iqn.2004-04.com.qnap" ]; then
    target_name=`echo "${target_name%.*}"`
fi

echo "${target_name##*.}"
..............................................

After creating the UNIX SHELL script, change it to executable:

[root@racnode1 ~]#  
                         chmod 755 /etc/udev/scripts/iscsidev.sh
                      

Now that udev is configured, restart the iSCSI service on both Oracle RAC nodes:

[root@racnode1 ~]#  
                         service iscsi stop
Logging out of session [sid: 6, target: iqn.2006-01.com.openfiler:racdb.crs1, portal: 192.168.2.195,3260]
Logging out of session [sid: 7, target: iqn.2006-01.com.openfiler:racdb.fra1, portal: 192.168.2.195,3260]
Logging out of session [sid: 8, target: iqn.2006-01.com.openfiler:racdb.data1, portal: 192.168.2.195,3260]
Logout of [sid: 6, target: iqn.2006-01.com.openfiler:racdb.crs1, portal: 192.168.2.195,3260]: successful
Logout of [sid: 7, target: iqn.2006-01.com.openfiler:racdb.fra1, portal: 192.168.2.195,3260]: successful
Logout of [sid: 8, target: iqn.2006-01.com.openfiler:racdb.data1, portal: 192.168.2.195,3260]: successful
Stopping iSCSI daemon:                                     [   
                        
OK  ]

[root@racnode1 ~]#  
                         service iscsi start
iscsid dead but pid file exists
Turning off network shutdown. Starting iSCSI daemon:       [   
                        
OK  ]
                                                           [   
                        
OK  ]
Setting up iSCSI targets: Logging in to [iface: default, target: iqn.2006-01.com.openfiler:racdb.crs1, portal: 192.168.2.195,3260]
Logging in to [iface: default, target: iqn.2006-01.com.openfiler:racdb.fra1, portal: 192.168.2.195,3260]
Logging in to [iface: default, target: iqn.2006-01.com.openfiler:racdb.data1, portal: 192.168.2.195,3260]
Login to [iface: default, target: iqn.2006-01.com.openfiler:racdb.crs1, portal: 192.168.2.195,3260]: successful
Login to [iface: default, target: iqn.2006-01.com.openfiler:racdb.fra1, portal: 192.168.2.195,3260]: successful
Login to [iface: default, target: iqn.2006-01.com.openfiler:racdb.data1, portal: 192.168.2.195,3260]: successful
                                                           [   
                        
OK  ]
                      

Let's see if our hard work paid off:

[root@racnode1 ~]#  
                         ls -l /dev/iscsi/*
/dev/iscsi/crs1:
total 0
lrwxrwxrwx 1 root root 9 Nov  3 18:13 part -> ../../sdc

/dev/iscsi/data1:
total 0
lrwxrwxrwx 1 root root 9 Nov  3 18:13 part -> ../../sde

/dev/iscsi/fra1:
total 0
lrwxrwxrwx 1 root root 9 Nov  3 18:13 part -> ../../sdd
                      

The listing above shows that udev did the job it was suppose to do! We now have a consistent set of local device names that can be used to reference the iSCSI targets. For example, we can safely assume that the device name /dev/iscsi/crs1/part will always reference the iSCSI target iqn.2006-01.com.openfiler:racdb.crs1. We now have a consistent iSCSI target name to local device name mapping which is described in the following table:

iSCSI Target Name to Local Device Name Mappings
iSCSI Target Name Local Device Name
iqn.2006-01.com.openfiler:racdb.crs1 /dev/iscsi/crs1/part
iqn.2006-01.com.openfiler:racdb.data1 /dev/iscsi/data1/part
iqn.2006-01.com.openfiler:racdb.fra1 /dev/iscsi/fra1/part

 

Create Partitions on iSCSI Volumes

We now need to create a single primary partition on each of the iSCSI volumes that spans the entire size of the volume. As mentioned earlier in this article, I will be using Automatic Storage Management (ASM) to store the shared files required for Oracle Clusterware, the physical database files (data/index files, online redo log files, and control files), and the Fast Recovery Area (FRA) for the clustered database.

The Oracle Clusterware shared files (OCR and voting disk) will be stored in an ASM disk group named +CRS which will be configured for external redundancy. The physical database files for the clustered database will be stored in an ASM disk group named +RACDB_DATA which will also be configured for external redundancy. Finally, the Fast Recovery Area (RMAN backups and archived redo log files) will be stored in a third ASM disk group named +FRA which too will be configured for external redundancy.

The following table lists the three ASM disk groups that will be created and which iSCSI volume they will contain:

Oracle Shared Drive Configuration
File Types ASM Diskgroup Name iSCSI Target (short) Name ASM Redundancy Size ASMLib Volume Name
OCR and Voting Disk +CRS crs1 External 2GB ORCL:CRSVOL1
Oracle Database Files +RACDB_DATA data1 External 32GB ORCL:DATAVOL1
Oracle Fast Recovery Area +FRA fra1 External 32GB ORCL:FRAVOL1

As shown in the table above, we will need to create a single Linux primary partition on each of the three iSCSI volumes. The fdisk command is used in Linux for creating (and removing) partitions. For each of the three iSCSI volumes, you can use the default values when creating the primary partition as the default action is to use the entire disk. You can safely ignore any warnings that may indicate the device does not contain a valid DOS partition (or Sun, SGI or OSF disklabel).

In this example, I will be running the fdisk command from racnode1 to create a single primary partition on each iSCSI target using the local device names created by udev in the previous section:

 

  • /dev/iscsi/crs1/part
  • /dev/iscsi/data1/part
  • /dev/iscsi/fra1/part


Note: Creating the single partition on each of the iSCSI volumes must only be run from one of the nodes in the Oracle RAC cluster! (i.e. racnode1)

# ---------------------------------------

[root@racnode1 ~]#  
                         fdisk /dev/iscsi/crs1/part
Command (m for help):  
                         n
Command action
   e   extended
   p   primary partition (1-4)
                          p
Partition number (1-4):  
                         1
First cylinder (1-1012, default 1):  
                         1
Last cylinder or +size or +sizeM or +sizeK (1-1012, default 1012):  
                         1012

Command (m for help):  
                         p

Disk /dev/iscsi/crs1/part: 2315 MB, 2315255808 bytes
72 heads, 62 sectors/track, 1012 cylinders
Units = cylinders of 4464 * 512 = 2285568 bytes

               Device Boot      Start         End      Blocks   Id  System
/dev/iscsi/crs1/part1               1        1012     2258753   83  Linux

Command (m for help):  
                         w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

# ---------------------------------------

[root@racnode1 ~]#  
                         fdisk /dev/iscsi/data1/part
Command (m for help):  
                         n
Command action
   e   extended
   p   primary partition (1-4)
                          p
Partition number (1-4):  
                         1
First cylinder (1-33888, default 1):  
                         1
Last cylinder or +size or +sizeM or +sizeK (1-33888, default 33888):  
                         33888

Command (m for help):  
                         p

Disk /dev/iscsi/data1/part: 35.5 GB, 35534143488 bytes
64 heads, 32 sectors/track, 33888 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes

                Device Boot      Start         End      Blocks   Id  System
/dev/iscsi/data1/part1               1       33888    34701296   83  Linux

Command (m for help):  
                         w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.


# ---------------------------------------

[root@racnode1 ~]#  
                         fdisk /dev/iscsi/fra1/part
Command (m for help):  
                         n
Command action
   e   extended
   p   primary partition (1-4)
                          p
Partition number (1-4):  
                         1
First cylinder (1-33888, default 1):  
                         1
Last cylinder or +size or +sizeM or +sizeK (1-33888, default 33888):  
                         33888

Command (m for help):  
                         p

Disk /dev/iscsi/fra1/part: 35.5 GB, 35534143488 bytes
64 heads, 32 sectors/track, 33888 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes

               Device Boot      Start         End      Blocks   Id  System
/dev/iscsi/fra1/part1               1       33888    34701296   83  Linux

Command (m for help):  
                         w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
                      

Verify New Partitions

After creating all required partitions from racnode1, you should now inform the kernel of the partition changes using the following command as the " root" user account from all remaining nodes in the Oracle RAC cluster ( racnode2). Note that the mapping of iSCSI target names discovered from Openfiler and the local SCSI device name will be different on both Oracle RAC nodes. This is not a concern and will not cause any problems since we will not be using the local SCSI device names but rather the local device names created by udev in the previous section.

 

From racnode2, run the following commands:

[root@racnode2 ~]#  
                         partprobe

[root@racnode2 ~]#  
                         fdisk -l

Disk /dev/sda: 160.0 GB, 160000000000 bytes
255 heads, 63 sectors/track, 19452 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14       19452   156143767+  8e  Linux LVM

Disk /dev/sdb: 35.5 GB, 35534143488 bytes
64 heads, 32 sectors/track, 33888 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       33888    34701296   83  Linux

Disk /dev/sdc: 35.5 GB, 35534143488 bytes
64 heads, 32 sectors/track, 33888 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       33888    34701296   83  Linux

Disk /dev/sdd: 2315 MB, 2315255808 bytes
72 heads, 62 sectors/track, 1012 cylinders
Units = cylinders of 4464 * 512 = 2285568 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1        1012     2258753   83  Linux
                      

As a final step you should run the following command on both Oracle RAC nodes to verify that udev created the new symbolic links for each new partition:

[root@racnode2 ~]#  
                         (cd /dev/disk/by-path; ls -l *openfiler* | awk '{FS=" "; print $9 " " $10 " " $11}')
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.crs1-lun-0 -> ../../sdd
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.crs1-lun-0-part1 -> ../../sdd1
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.data1-lun-0 -> ../../sdc
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.data1-lun-0-part1 -> ../../sdc1
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.fra1-lun-0 -> ../../sdb
ip-192.168.2.195:3260-iscsi-iqn.2006-01.com.openfiler:racdb.fra1-lun-0-part1 -> ../../sdb1
                      

The listing above shows that udev did indeed create new device names for each of the new partitions. We will be using these new device names when configuring the volumes for ASMlib later in this guide:

 

  • /dev/iscsi/crs1/part1
  • /dev/iscsi/data1/part1
  • /dev/iscsi/fra1/part1



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