A Case For Virtualization: Rooms To Go

The following case study is the third of our five-part series on the gains and pains of server virtualization.

A series on the gains and pains of server virtualization
Part One:
Case Study: Orchard Supply Hardware
Part Two:
Roswell Park Cancer Research Institute
Part Three:
Rooms To Go
Part Four:
Next Up In Part 4: Owen Bird Law
A proponent of "virtualizing everything" is Jason Hall, IT director of Rooms To Go, a retailer of coordinated furniture sets through 150 stores in Texas and the Southeast. Founded in 1991, it's now the fourth-largest independent furniture seller in the U.S., the company says.

As Rooms To Go grew, Hall expanded its data center, eventually filling five 42U racks with 165 rack-mount servers. Three years ago, he had planned to add three more racks, and once those were filled, move to a new data center. Instead, Hall put 200 virtual servers on one chassis holding nine Hewlett-Packard blades, which reclaimed space. The chassis is only half full, leaving Rooms To Go plenty of room for expansion. Meanwhile, the data center's electricity consumption, including rooftop air conditioning consumption, has decreased by 20% to 25%, he says.

Unlike Windows-only shops, however, Rooms To Go had an additional 19 IBM AIX servers running point-of-sale, warehousing, distribution, finance, and customer service systems. Hall's team virtualized them as well, consolidating to two AIX servers. Now the problem is monitoring all those VMs and tracking each new one as it's created with an IT staff of six. The management system for VMware doesn't extend to the AIX VMs.

"We're at a point where we're 90% to 95% virtualized. We're moving toward being 100% virtualized. We won't make it," Hall says. "There's always one more application that won't be supported in a VMware environment." Some application vendors still refuse to extend support of their software running in a virtualized environment.

To get to such a high level of virtualization, Rooms To Go has had to make good use of VMware tools, such as Dynamic Resource Scheduler, which shifts resources among running VMs or shifts the VMs themselves to servers with more resources. As a result, it has gained much greater flexibility in meeting business demands. End user applications have been virtualized on Citrix AppServer, running in 23 VMs on the new HP blades. Likewise, Exchange e-mail and SQL Server databases run in VMs. I/O for the VMs subsequently has become more of an issue, and Hall says his staff is studying how best to upgrade the underlying SAN.

Monitoring and managing both the IBM AIX and VMware/HP blade virtualized environments is "our biggest problem," Hall says. In addition to VMware monitoring tools, he has added CA Virtual Assurance for Infrastructure Managers, capable of viewing both environments.

The monitoring tool ties into CA Spectrum Infrastructure Manager (for which an enterprise license starts at $200,000) and can provide root cause analysis of problems, whether a fault is occurring in a hardware component or software. It helps diagnose potential problems before they bring systems down, Hall says. As a result of virtualization and Hall's chosen toolset, Rooms To Go is achieving 50% to 60% CPU utilization rates, compared with much lower rates--under 15%--when each server ran one application.

Hall would like to push utilization higher, but he sees 80% as a ceiling he shouldn't cross. For when CPUs start reaching 80%, Hall has a policy telling VMware's Dynamic Resource Scheduler to kick in and start relieving the server by moving workloads. "Monitoring and automation in the virtualized environment help us run the data center," he says. "It makes it much easier to manage."

Next Up In Part 4: Owen Bird Law