Supply-chain software as a service (SaaS) company SupplyScape Corp. moved from DAS to a 3PAR Inc. SAN with thin provisioning and virtual snapshots to grow its storage capacity in phases.
Since installing 3PAR's InServ Storage Server a year ago, SupplyScape's capacity utilization has gone up 50%, according to director of operations and architecture John Kordash. By starting with DAS and then moving to a SAN as capacity needs increased, SupplyScape avoided building a large, expensive infrastructure up front.
That growth has necessitated a complete redesign of the company's DAS infrastructure for its Oracle Corp. databases. That redesign included SupplyScape's moving to 3PAR storage, and it currently runs two InServ S400 Storage Servers.
Kordash says the company anticipated shifting to a SAN eventually, but went with DAS when it started in 2004 to stand up the quickest, cheapest architecture it could. "It was clear what direction the data growth was going," he says. "We chose DAS to get into the game and then it became a discussion internally about when and how to get to a more flexible and scalable architecture."
The decision to move from DAS to SAN isn't as obvious as you might think. Some SaaS providers, such as Google, have stuck with DAS because of its low-cost commodity components. Industry experts suggest DAS may be making a comeback in the enterprise for specialized applications such as Oracle because of recent boosts in server processing power and disk drive size.
But Kordash says given SupplyScape's rapid growth and the demanding uptime service level agreements (SLAs) it offers its customers, DAS couldn't scale quickly or nondisruptively enough to meet his company's needs. But he says most of the storage vendors he evaluated didn't offer the redundancy and availability he required at the low capacities he was starting with.
Approximately 18 months after SupplyScape first opened for business, Kordash began consulting with 3PAR, which at the time was one of the few companies to offer thin provisioning with its storage. Thin provisioning would let SupplyScape start small, but show its hosts large volumes that it would come to fill with more physical capacity over time.
"What I especially liked about 3PAR was that when we added storage, we could also add it to existing volumes instead of just adding new volumes on top of the old," says Kordash. He was also impressed with 3PAR's Virtual Copy snapshots, which require no additional storage capacity overhead when deployed.
Using InServ with thin provisioning helps SupplyScape avoid wasting capacity. Kordash says that with DAS, 300% more storage had been available than had been used. In addition to saving hardware capacity for production storage with thin provisioning, Kordash says space-efficient snapshots have saved his company from having to deploy a separate test/dev infrastructure.
The consolidated system serves the company well for now, but Kordash says he hasn't ruled out going with a distributed parallel or clustered system long term if data continues to grow. "It's not a matter of either/or," he says of the comparisons between DAS, SAN and clustered systems. "It's a sliding scale."