The City of Coquitlam, B.C., backed into virtual storage 18 months ago as part of an upgrade from VMware Inc.'s ESX Server 3.0 to Version 3.5. When the Vancouver suburb's IT shop discovered its aging Hitachi Data Systems (HDS) Corp. Thunder 9570 disk arrays weren't certified to work with VMware's new server virtualization software, it went looking for a new storage back end. After considering NetApp Inc.'s V-Series and IBM's SAN Volume Controller (SVC), Coquitlam settled on HDS' Universal Storage Platform VM (USP VM) -- the lower-end counterpart of the vendor's USP V storage system -- in part because of the potential benefits of controller-based storage virtualization.The city figured that virtual storage would not only help to extend the life of its Thunder 9570s, but also potentially front its Nexsan Corp. ATABeast backup/archive appliance to enable the IT staff to view all of its storage systems as a single pool.
Implementing virtual storage in tandem with a new VMware server farm, a new QLogic Corp. SANbox 9200 core switch and the new HDS USP VM SAN gave the project the feel of a greenfield deployment, even though Coquitlam already had a SAN. The city spent two to three weeks integrating its original SAN with the new SAN fabric with the help of Compugen.The only glitch was a one-day outage related to a power struggle between the new QLogic switch and the old Brocade Communications Systems Inc. switches. Coquitlam wanted its new QLogic switch to be the master, but an old Brocade switch claimed control, triggering a day of troubleshooting with Compugen. "Once we figured out the command, it came up," Browett said. "We could have been done in a half-hour if we knew that command." Virtualizing LUNs from the city's different storage systems was a simple process, according to Browett. "You make sure the LUN is inactive, present it and say, 'I want to virtualize that LUN.' That's it. Then you bring the server back up that uses that LUN," he said. The IT staff does have to take the LUN offline for approximately 15 minutes to virtualize it, but that's the main challenge, according to Compugen's Tolentino. "Most IT shops run 24/7, and you still have to take it down. But instead of having a bigger outage, there's a smaller window [with the HDS system] because you just have to virtualize the LUN. You don't have to move data," Tolentino said. The City of Coquitlam now has approximately 20 TB of virtual storage through its USP VM and hasn't noticed an impact on performance or done any special monitoring or management. The city plans to migrate the remainder of the LUNs from its Thunder 9570s to the USP VM during the next year. "That's for me where the storage virtualization's going to come into play," Coquitlam's Browett said. "As I need to move my data around as storage arrays become end of life or end of support, I can slowly migrate that data off of the old SAN into a new SAN or a new storage array without creating any downtime or other issues for my users."