Virtualization helps school with storage woes
- 21 May, 2007 17:20
When it comes to flexible enterprise storage, the University of Florida College of Veterinary Medicine doesn't horse around. Over the last six months, the college has been putting its 7TB storage area network through its paces, using it for nearline backup and primary storage, and has this insight to share: Storage virtualization is the cat's meow.
The tale begins in late 2005, with UFCVM trying to cope with staggering volumes of advanced, multimedia diagnostic data. The college treats tens of thousands of animals each year -- in 2006 it handled more than 40,000 cases, it says. The pain point was backups: The window required for nightly backups to tape had begun to outstrip the time available to complete them.
To fix the problem, IT staff knew they wanted a nearline, disk-based SAN. They considered the usual proprietary storage vendors and realized their $US100,000 budget wouldn't go very far, says Sommer Sharp, systems programmer for UFCVM.
So Sharp decided to piece together storage capacity from affordable vendors and write the management pieces in-house. Then she learned of Storage Virtualization Manager (SVM), a virtualization appliance from StoreAge Networking Technologies, now owned by LSI Logic.
SVM, which sits between a company's servers and the SAN (or SANs), takes low-volume snapshots of production data and sends them simultaneously to nearline backup disks and tape libraries. Because it operates outside the data path, it does not drag performance down, its maker says. It also lets storage volumes be moved among SANs regardless of the brands of the servers or storage devices involved. In this way, it creates a single, flexible pool of storage.
The college's SAN setup is a little unusual, too. The servers use iSCSI to communicate with their allocated space on the SAN, but the storage, Nexsan Technologies' SATABlade systems, uses Fibre Channel to work with the SAN's control appliances. These include the SVM, as well as a Troika Accelera switch (now QLogic's SANbox 8000).
The Accelera translates iSCSI commands, such as presenting the logical unit number to the server. Meanwhile, Sharp can use the servers' Microsoft iSCSI software, negating the need to put third-party SAN software on them. The setup is virtual and economical. "We went with the SATABlades due to cost but have been impressed with their performance," she says.
The operation was successful: The SAN reduced backup times by half, and the project came in under budget, she says.
It was later that the SAN grew really interesting, however. Even though LSI Logic bills SVM as a backup device, within a few months Sharp began to see that, because of the virtualization, she no longer needed to distinguish between inline and nearline storage.
Page BreakProvisioning is a painless matter of moving volumes to any server that needs it, so live data can be managed as easily as backups. UFCVM went to town. Within the last six months, it has filled 5TB of the SAN's 7TB capacity with live data. It uses 500GB for nearline backup space, but backups also are dumped immediately to tape.
Sharp says she loves the hardware independence the appliance enables. For instance, although the SAN uses iSCSI, "I could put traditional SCSI volumes out there, too. It doesn't matter what hardware I put behind the SVM appliance, or what operating system I put in front of it," she says. When the college buys servers, all storage is left to the SAN.
With a few clicks from the SVM's management screen, Sharp allocates the desired amount of storage, "and, boom, it shows up in the device." It doesn't matter what that device is. During the testing phase her team even provisioned a laptop: "We did it for grins. We gave a laptop over a wireless connection a terabyte hard drive." But Sharp says giving clients direct SAN access is not going to happen. For security and stability, the SVM switch is on its own segregated link to the servers.
Virtualized storage offers college users other never-before-possible options, too. The SVM device lets a snapshot of live data be placed on a server easily; that gives developers a copy of a real database for testing purposes.
On Sharp's SAN project wish list, when budgets allow, is building a second, mirrored SAN for business continuity. SVM has a mirroring module that would make the implementation of a dual-failover SAN a fairly painless process, she says.
In the meantime, UFCVM is working on server clustering to speed the performance of the entire server and storage infrastructure. It has been using an informal cluster by hooking its three Microsoft servers into the SAN via Microsoft's Distributed File System (DFS) root -- making the Microsoft software act "as the traffic cop," Sharp says.
By the end of June, she expects to have implemented Microsoft's clustering services, supported by Server 2003. Among other benefits, this will give the SAN higher availability than DFS root does.
Painless, flexible, inexpensive: What's not to love about today's New Data Center virtualized storage?