As Published In March/April 2005

Streamlining Storage Management
By Fred Sandsmark

Talk America leverages new Oracle Database 10g features for storage management.

Managing storage has always been an arduous task for administrators—locating and removing I/O hotspots, provisioning storage, and dealing with fragmentation are time-consuming activities. And the advent of storage-area networks (SANs) or network-attached storage (NAS) introduced additional dependencies to the process of provisioning storage for the database environment.

Managing storage in Oracle environments is now easier, thanks to Automatic Storage Management (ASM), a new feature of Oracle Database 10g. ASM integrates the functionality of a file system and a logical volume manager (LVM) into the Oracle database kernel.

Rather than using third-party file systems and volume managers to store Oracle data, ASM distributes all files—datafiles, log files, and control files—onto DBA-defined groups of storage devices. Because it's a part of Oracle, ASM understands the content of the files it manages and can rebalance data in ways that an LVM or OS file manager can't. As an added benefit, ASM can deliver the performance of raw I/O—without the hassles.

ASM makes manual I/O performance tuning unnecessary and improves storage utilization. It prevents the creation of storage hotspots that can lead to performance and reliability problems. With ASM, DBAs can rebalance files across a group of disks with a single command when storage is added or removed. ASM can even reconfigure active storage without taking the database offline.

ASM employs a new type of instance, ASM instance, to manage and apportion storage. A single ASM instance can handle multiple databases on a given server. The databases read and write their own data, and the ASM instance reads and writes during rebalancing operations.

By combining a vertically integrated file system and volume manager built for Oracle database files with storage virtualization normally associated with SANs, ASM provides Oracle DBAs with benefits such as easy manageability and high availability, within the Oracle environment.

Talk America, a provider of local and long-distance telephone service in the U.S., uses ASM to manage some 60 terabytes of data on EMC DMX 2000 and EMC 8830 storage systems. "Historically, you dedicated storage to different disparate systems," says Laurence Grant, Talk America's vice president of enterprise computing systems. "But with my storage pooled together, I can share the storage across multiple different systems. So when I need to grow storage or I need to shift storage requirements around, it's all virtual through ASM."

ASM helped convince Talk America to make the move to Oracle Database 10g. "Automatic storage management is probably one of the driving factors that propelled us into Oracle 10g," says Vishal Anand, the company's senior database project specialist and administrator. "Being a DBA myself, I understand how much manual labor is required in allocating and managing storage space and the mistakes that can be detrimental. ASM seamlessly takes that away. It automates that whole procedure."

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For Anand, this seamless automation translates into big time savings. "For example, if I had to go and allocate 5 terabytes, it would take me a few days of communicating with the storage administrator or the system administrator, making sure we're on the same page," Anand continues. "In ASM, it takes me less than an hour. Our ROI impact is huge."

Grant and Anand appreciate that Oracle Database 10g and ASM are constantly adjusting to Talk America's changing environment in the background, without distracting them from more important tasks. "I'm able to focus on what I need to do as a DBA," Anand says. "I'm able to spend more time with the development team and ensure that my whole environment is running up to par. As we create objects and add space to them, ASM in the background is rebalancing the blocks. Our storage is being optimized automatically." Anand intends to use ASM to migrate Talk America's data to a new disk frame he's bringing online. "ASM will rebalance our data to the new EMC frame seamlessly," Anand says. "Using ASM, we get a seamless migration without the cost of any downtime."