This is one of three case studies on the merits of server virtualization in the data center. Others detail SAN technology considerations when virtualizing and improving IT efficiency with server virtualization.
In this economy, smaller organizations grapple with limited IT budgets and staff. As companies struggle to extend the working life of existing computing platforms, they usually turn to longer server refresh cycles and fewer new technology deployments. Eventually, aging computing platforms become liabilities, creating maintenance challenges and limiting the deployment of new technologies, such as server virtualization software. However, when budgets open up for new systems, an organization can often add the virtualization layer and migrate applications into virtual machines (VMs), resulting in a quantum leap forward in efficiency and application availability.
A server refresh gives way to server virtualization software
For Sports Physical Therapy of New York, a healthcare provider with 24 locations across New York, a series of servers purchased around 2005 started to show their age. Uptime had become problematic, and long-expired warranties left the IT department scrambling for self-maintenance.
"I had one crash and spent between 24 and 30 hours rebuilding it," said Jeffrey Shuron, the company's director of IT. That experience prompted Shuron to re-evaluate the availability of email, databases, user information and other business workloads in the organization.
Shuron spent more than a year experimenting with Virtual Iron Software, Microsoft Hyper-V and VMware server virtualization software, hoping to better understand the potential benefits of virtualization and server consolidation. Shuron ultimately selected VMware as their server virtualization software of choice because of its maturity and feature set (including vMotion and high availability), and carefully evaluated the behavior and performance of the principal applications that would become VMs.
Actually deploying server virtualization and migrating physical workloads into the virtual environment had to wait until a server refresh cycle brought on three Dell PowerEdge R710 servers with enough computing headroom to accommodate multiple VMs on each physical host.
Shuron tried various techniques to migrate the physical workloads to VMs. One approach used live migration -- server virtualization software virtualizes the workload without disruption. The alternative used "cold cloning," where a server is taken out of service, VMware software is loaded, and the workload is moved from a physical to a virtual host. This can leave the server (and the application) unavailable for hours.
File and printer services as well as user data-related applications moved over perfectly with live migration. The SQL Server, however, did not run properly after migration.
"[With] live migration, after a day or two, the virtual instance would fail so I'd have to revert back to the physical server," Shuron said. "I ended up doing a cold migration, and that went off without a hitch."
The email and Active Directory server were also cold cloned right from the start. The three R710 servers eventually hosted a total of 12 VMs, and the entire migration process and configuration changes for all VMs took an estimated 36 hours to complete.
Other than the SQL Server migration snafu, Shuron reported no significant problems in migrating the workloads from physical servers to VMs, but the organization did need to purchase a new switch to accommodate the network demands of the VMs now residing on the Dell servers. Each of the servers also connected to a Dell storage area network (SAN), eliminating the need for local storage.
"We use [the Dell SAN] for snapshots," Shuron said. "And with high availability, it doesn’t matter what physical host fails; all the information is on the SAN."
Getting the most out of virtualization
The company eventually hopes to expand virtualization’s role in the data center beyond server virtualization software. Currently, Shuron is piloting a 10-desktop virtualization program with VMware View. While there is no timetable for deployment, the goal is to eventually centralize the desktops used in the organization's 24 locations.
Shuron's enthusiasm for the use of virtualization is easy to understand -- the company is a one-person IT shop operating on a shoestring budget. The message is that virtualization has evolved as a practical and approachable technology that is suited for even small IT organizations.
"If I can do it, with a little work, anyone can do it," Shuron said.
Stephen J. Bigelow, a senior technology writer in the Data Center and Virtualization Media Group at TechTarget, has more than 15 years of technical writing experience in the PC/technology industry. He holds a bachelor of science in electrical engineering, along with CompTIA A+, Network+, Security+ and Server+ certifications, and has written hundreds of articles and more than 15 feature books on computer troubleshooting, including Bigelow’s PC Hardware Desk Reference and Bigelow’s PC Hardware Annoyances.
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