On the wide-open expanse of the Canadian prairies, space isn’t at a premium the way it is in, say, downtown Toronto or Vancouver. But disk space is just as precious here as anywhere else, and the promise of being able to use it more efficiently has led the city of Saskatoon to storage virtualization.
Virtualization hides the complexities of different storage devices behind a single interface, turning assorted systems into a single pool of storage that is easily shared among different servers and applications, yet uses different types of storage.
Saskatoon has about 2,500 employees, around 1,000 desktop PCs, some 70 servers, about 10 terabytes of storage — and almost 30 separate businesses, says Peter Farquharson, manager of technology integration in the city’s corporate information services department.
“”There’s road crews, there’s tourism, there’s land sales, there’s property management — there’s all sorts of different stuff.””
The city’s IT environment isn’t as complicated as it could be, though. All servers are based on Intel Corp. chips running Windows, and most software is off-the-shelf packages. “”The in-house development we do is mainly integration between packages,”” Farquharson says. And the disk storage is all IBM, consisting of a FAStT600 disk system, two older IBM 3526 disk systems and an IBM Shark Enterprise Storage Server.
Storage is allocated to different servers as required. Before virtualization, if a server ran out of storage, space would have to be re-allocated to solve the problem. This was awkward and time-consuming, and often had to be done outside business hours to avoid disrupting applications. This in turn led to overtime costs.
The hassle of provisioning storage is one of the major factors drawing attention to storage virtualization, says Stephanie Balaouras, senior analyst with consulting firm Yankee Group Inc. in Boston. Re-allocating storage can take from a few hours to as much as a week, she says, and often requires expertise specific to different vendors’ storage devices. “”People will actually over-provision storage so they don’t have to do it too often.””
Kyle Foster, general manager of storage sales at IBM Canada Ltd. in Markham, Ont., says even well-run IT shops often use 40 per cent or less of their storage capacity. He claims storage virtualization can improve this to 60 per cent or better. “”The justification becomes very easy,”” he says.
Balaouras says the savings for some organizations can reach $500,000 to $1 million within a couple of years.
Last spring, Saskatoon bought its first IBM TotalStorage SAN Volume Controller (SVC), setting it up as an intermediary between servers and the FAStT600 and one of its 3526s. The IS staff created three storage classes — high performance, medium performance and low performance or archival storage. Servers need a single storage driver to talk to the SVC, so storage can be reallocated without making any changes on the servers, Farquharson explains.
Setting up the SVC was simple, says Farquharson. “”It came in a box on Monday, we put it in the rack on Tuesday, configured it on Wednesday, put it into production on Thursday.”” IBM representatives came in for a couple of days to help. Understanding the system is a matter of “”just a couple of key concepts you’ve got to get your head around,”” Farquharson says. A couple of staff members are trained to allocate storage, and other than that, “”the thing just runs.””
Late in 2004, the city bought a second SVC, connecting the Shark to it. Although the city’s current disk systems are all from IBM, Farquharson says the company’s recent addition of support for other storage vendors’ hardware is a plus. “”It’s very nice, because it gives us more options, because we can pursue other vendors,”” he says.
IBM also offers technology to virtualize tape, but not integrated with the SVCs. Farquharson hopes that will come. “”What I’m hoping they’ll do in the future is virtualize tape to the point where I can put a tape library behind (the SVC),”” he says. Foster says this is technically possible, but IBM hasn’t seen strong customer demand. In time, he says the company plans more integration.
Now that it has virtualized storage, Farquharson says the city can manage storage more tightly, reducing its spending on storage hardware. And there are other cost benefits. “”There’s been a reduction in overtime because we can do a lot of things on the fly now, instead of having to come in at night.””