Virtual Machine Manager Levels Load For Colorado AgencyVirtual Machine Manager Levels Load For Colorado Agency

Last fall, as a Colorado housing agency's virtual servers began to slow, manager Steve Perkins concluded that either the Dell two-way hosts couldn't keep up with demand or he was running out of disk space on his Fibre Channel storage network.

As it turned out, it was neither.

A local consulting firm hired to troubleshoot the problem, Long View Systems, found he had plenty of spare CPU power and good disk capacity still available. But he was experiencing heavy I/O contention as his 50 virtual machines sought to read and write to one of his four shelves, the 15-unit disk arrays around which he organized his storage area network.

Long View Systems had applied a virtual machine management tool, Akorri's BalancePoint, and spotted the I/O problem as it watched his virtual machine operations. BalancePoint also formulated several recommendations under "what if" scenarios that helped him find a way out of the dilemma.

When BalancePoint drew a picture of what was wrong with his environment, it showed some I/O channels "running in the red, which is bad," he said. As he reconfigured storage, the display changed to green, or spare capacity available.

"Last September, we were in reactive mode -- just do things to get it fixed. Now we have the ability to put in a much better storage environment," said Perkins.

Instead of spending $250,000 on new Fibre Channel disks, Perkins instead realigned the way his logical storage units were using his shelves to spread the I/O load.

"We had some system logs on the same disks as [Microsoft] SQL Server data," said Perkins, manager of infrastructure technology, in an interview. The Colorado Housing and Finance Authority is a data-intensive environment as it issues state-backed bonds to raise funds and underwrites home loans to first-time or low- and middle-income buyers in the state.

"The SQL Server people wanted me to put in their own dedicated disks. We're not doing that," he said. Instead of plopping down $250,000 for disk drives he didn't really need, Perkins began planning his next move to improve his virtualized environment, implementing a virtual disk library at the agency's headquarters near the Coors Stadium in Denver. With a virtual disk library, he'll be able to do disk-to-disk backup instead of the slower disk-to-tape backup. Then he'll expand the capacity of his disaster-recovery site and make better use of those secondary resources.

The agency has virtualized eight two-way Dell servers hosting a total of 50 VMware ESX-based virtual machines on which it manages its lending data. "We're a very small shop," said Perkins. Eighteen of the company's 107 employees are in IT; tools that give him analysis of how his infrastructure operates are valuable in view of his limited resources.

BalancePoint has been a big enough help on the I/O front that he wants Akorri to extend it into a deeper view of virtualized storage area networks. That way he will be able to use the same tool to get a direct view how his virtual machines are working with his SAN. "We're actively pushing them to get them to work with LSI Corp.," the agency's pending virtual disk library supplier. If Akorri can provide a view of the virtual storage network, it will give Perkins the more comprehensive view of his environment that he needs.

BalancePoint also can't see his virtualized applications directly, but it has offered an indirect look at how well they are running as he moves them one by one from SQL Server 2000 to SQL Server 2005. As each application is migrated, he sees how much it increases the load on the virtual machines running SQL Server.

As he builds out his virtualized environment, Perkins thinks there's hidden cost savings in the new arrangements. "I don't need to keep all my data on expensive Fibre Channel disks." He'd like to move some of it to SATA disks instead and invest the savings elsewhere.

In the meantime, he figures investing in a virtualization management tool is one of the better expenditures he made last year. BalancePoint is priced at $7,500 per 5 TB of storage in use. Akorri is based in Littleton, Mass., and launched BalancePoint 1.0 in January 2007. BalancePoint 2.0 became available in May.