When it comes to flexible enterprise storage, the University of Florida College of Veterinary Medicine (UFCVM) 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.
The tale begins in late 2005, when UFCVM was 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 realised their US$100,000 (NZ$132,000) 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 Virtualisation Manager (SVM), a virtualisation 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 set-up 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 virtualisation, she no longer needed to distinguish between inline and nearline storage.
Provisioning 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.
Virtualised 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.