Cutting the fat is not just a health trend for humankind. Space shortages are driving data centers to get skinny, too, by moving from physical to virtual machines (VMs). But for Pensacola, Fl.-based HealthWare Corp., even adding disk space to servers to accommodate more VMs was too heavy a load. So, the healthcare software vendor went on a mission to put its virtual machines on a diet.
HealthWare was an early adopter of virtualization. A Microsoft shop, HealthWare signed up for Microsoft Virtual PC when it came out in June 2001, started using Microsoft Virtual Server with its February 2004 beta and hasn't looked back.
Like many software vendors, HealthWare uses virtualization in its testing lab to ensure the compatibility of its software with clients' computers. Without virtualization, setting up multiple instances of operating systems with various service packs, hot fixes and Web browsers can take hours. But with virtualization, HealthWare "can automate VMs, script the creation of a VM, the start of a machine, [run an app] and so on," said Walter J. Voytek II, CEO, president and founder of HealthWare. The virtualization capability allows HealthWare to test its products overnight.
Being able to reset a VM back to an earlier stage is also valuable, Voytek said. "The main reason for bringing it back to the prior state is to make sure you can test from a known starting point each time without having to 'rebuild' a virtual machine each time."
HealthWare retains test VMs in case a new client has a similar build. The problem is that storing a lot of large VMs can quickly eat up the space on a hard drive. Buying more disk space wasn't too much of a problem, Voytek said, since hard disks are cheap. But adding disk space did have its downside -- the downtime required for installs.
Then Voytek read a blog about a VM shrinking program by Invirtus Inc. called VM Optimizer. After further research turned up more positive reviews, his team tried a trial release.
Honey, I shrunk the VMs!
VM Optimizer came as advertised. "It did what it said, and it did it simply," Voytek said.
During initial tests, Voytek's virtual machines shrunk from 2.4 GB to 1.3 GB. On average, he found it saved 50% of his hard disk space. In some instances, VMs shrunk to two-thirds of their original size.
Virtual Server comes with its own shrinking system, Virtual Disk Precompactor, which removes unused space on a virtual hard disk. But, according to Voytek, VM Optimizer does more in less time.
"VM Optimizer goes a huge step beyond Precompactor," said Voytek. "It removes pieces of software that aren't really used like Pinball and the old MSN client that shipped when Windows XP came out. In a virtual environment, you would never use those, so why not save space?"
VM Optimizer also removes folders no longer in use from older service packs and Windows Updates freeing up hundreds of megabytes of disk space.
Voytek reported no faults with the relatively new software. It installed with one click, and -- assuming you don't change the defaults -- it installs automatically. "When it's done, it shuts down the machine, you use the Virtual PC or Virtual Server compact function, and it's done," he said. "When you're done, you end up with the smallest usable image you could get."
Lifelong VM fitness
Any IT pro who regularly installs and uninstalls programs on a virtual machine would benefit from running VM Optimizer regularly to keep VMs in shape, Voytek said, even though it won't have the same dramatic effect as on initial runs.
Going forward, HealthWare plans to expand its use of virtualization beyond its testing environment and pare down its production server load. "Our goal is to go from six or seven [physical] servers used for day-to-day operations to two physical machines," Voytek said. New Microsoft licensing rules paired with virtualization-optimized processors should allow two physical servers to run four virtualized servers each, helping Voytek reach his goal.
With VM Optimizer at his disposal, new chips running his operating systems and less hardware in his shop, Voytek thinks he can keep his test and production servers lean and mean from now on.