When Houston-based electrical equipment distributor Wholesale Electric Supply Co. decided to centralize management of server resources by virtualizing with VMware, it also needed to install a storage-area network (SAN) and I/O virtualization switch to keep infrastructure costs from spiraling.
Bill Fife, director of IT at Wholesale Electric Supply, said he managed to get funding for a new Compellent Technologies Inc. Storage Center storage system and a Xsigo Systems Inc. I/O Director despite the economic downturn last fall.
"A SAN is necessary for [server] virtualization," he said, adding that server virtualization is necessary for cost-effective data center management.
Fife first checked out an EMC Corp. SAN, but found EMC storage too expensive. "I couldn't convince myself EMC was a good financial move so I certainly couldn't convince my boss," he said. Reseller CDW Corp. wanted him to talk to a representative from Hewlett-Packard (HP) Co.'s LeftHand Networks, but Fife said he didn't like that LeftHand's iSCSI SAN is based on server hardware.
Compellent, which Fife encountered at a midsized enterprise IT conference, turned his head with its Data Progression, thin provisioning, snapshots and replication software. "That eliminates my need to have third-party [host-based replication] apps replicating database updates between two separate SANs," he said.
The distributor is now running 1U diskless physical servers that boot from SANs at the company's primary location as well as at a secondary DR site. "We can build an ESX boot image, do a local replay and boot almost an infinite number of ESX servers from that," Fife said.
Xsigo I/O virtualization to storage cuts down power and cooling
Wholesale Electric Supply also consolidated the number of I/O cards installed in each physical server to cut down on power. Xsigo's I/O Director sits between physical hosts and the SAN switch. Instead of installing separate physical network interface cards (NICs) for Ethernet and host bus adapters (HBAs) for Fibre Channel (FC), the Xsigo director uses dual InfiniBand adapters to present virtual NICs and FC HBAs to each host.
"For a lot of people who have VMware, one or two network cards aren't enough," said Brian Trudeau, president at Wholesale Electric Supply's local solutions provider, Tradentrix Inc., which helped with the Compellent and Xsigo installations. "I've seen all the way up to six or eight network cards in bigger servers."
The I/O Directors give Wholesale Electric Supply 16 virtual NICs available for virtual servers. "You can logically add or remove them through the Xsigo interface and never have to touch the physical box ever again," Trudeau said. "You couldn't present that many physical NICs with a 1U device. You'd probably need maybe a 3U or 4U server, more rackspace and more heat to contend with."
Wholesale Electric Supply still needs to use Cisco Systems Inc. FC switches, but Xsigo helps them get more bang for the buck out of the 4 Gbps FC MDS switches.
" "Instead of having each server with a 4 gig Fibre Channel port, why not try to run as much I/O down the same Fibre Channel port as possible?" Trudeau asked. "Otherwise you're just managing bandwidth with a 1:1 relationship and it gets expensive."
With dual Xsigo directors and dual MDS switches, along with MPIO from each host to the network, Wholesale Electric Supply has four paths from each server through each volume on the SAN. "The costs of trying to do that in the physical world would just be … expensive is probably an understatement," Fife said.
However, it's been tougher to convince application administrators than upper management when it comes to the benefits of consolidation and virtualization, Fife said. That's the main reason just 1 TB of the company's roughly 5 TB of Windows databases has been migrated to the Compellent SAN.
"Even though they see that it works, and the SAN gets much faster throughput and IOPS, it's unfamiliar," Fife said. "They've had a long history in IT, and they like to be able to walk over and touch things. The concept of putting it on a SAN where they really don't know where it is and showing a chart with data progression, this is in tier 1 and this is in tier 3, they can look at it and get kind of cross-eyed. It's just a totally new way of thinking about things."