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Virtualization users beware: Sprawl is real

Virtual machines are quick and easy to create, leading to virtual machine sprawl in many data centers.

If physical and virtual machine (VM) management practices aren't put in place from the get-go, future data centers will suffer from virtual machine sprawl, say virtualization practitioners.

For more on virtual sprawl:
Networking and virtual server sprawl: The hidden costs of server utilization

Virtualization sprawl prevention; best practices

According to panelists at the "Best Practices for the Data Center of the Future" session at VMworld in San Francisco last month, VM sprawl quickly becomes an issue because virtual machines are so easily created and moved.

"The biggest issue in the data center surrounds management of the physical and virtual environment," Egenera Inc. founder and Chief Strategy Officer Vern Brownell said during the panel discussion.

I can quickly look at the whole AET virtual server farm quickly, easily, and without having to go and find them hidden under tables and desks.
Chris Stucker,
manager of systems, network and servicesApplied Extrusion Technologies Inc.

Chuck Brust, a lead systems engineer who is responsible for virtualization at the Mayo Clinic in Rochester, Minn., said that at first, his IT team jumped into virtualization full force, and every user who needed a virtual machine got one without much consideration for management.

"When we started out with virtualization, we thought, 'VMs are easy and cheap, so let's go; let's create as many as we need.' We ended up with several hundred more machines than we actually needed," Brust said.

Brust was running 2,500 physical servers at Mayo Clinic's data center before going to virtual machines. After about nine months of migration and establishment of virtualization ground rules to prevent sprawl, the clinic is down to 50 physical servers running 700 virtual machines running both VMware and Virtuozzo , Brust said. His data center is now about 40% virtualized, with a goal of 60%.

His advice to session attendees: Formulate guidelines for creating VMs from the outset. "It's important early on to get processes in place that specify who can create a VM and why," Brust said.

Containing physical server sprawl
But while virtual instances can easily spiral out of control, that's arguably a better problem than having too many unmanaged servers. Applied Extrusion Technologies Inc. (AET) was contending with the expense of physical server sprawl given its roughly 75 servers and PCs acting as servers spread around its Terre Haute, Ind.-based data center.

Chris Stucker, manager of systems, network and services for AET, virtualized the data center with Virtuozzo to put a stop to sprawling physical machines. To avoid the same sprawl issues from happening with virtual machines, Stucker allows only one admin to create VMs, and only with his approval.

"There was a similar policy around putting 'servers' into play back in our physical days, but it was harder to enforce, as anyone could grab any old server or even PC and do their own thing with it," Stucker said.

"Keeping it all under control is much easier now that any physical server would attract immediate attention, and I can quickly look at the whole AET virtual server farm quickly, easily, and without having to go and find them hidden under tables and desks and in cubicles," Stucker said.

AET now runs about 45 Virtuozzo virtual environments on three IBM blade servers with dual-core, 2 GHz processors and 8 GB of memory. All are running Windows and are connected to a storage area network.

In addition to setting up the ground rules regarding when and why VMs are created, some management software options help users control their physical and virtual infrastructure, like FastScale Virtual Manager from Sunnyvale, Calif.-based FastScale Technology Inc.

For virtual environments, AET uses the management tools provided by Virtuozzo; for physical machines, management tools vary by server, Stucker said.

Let us know what you think about the story; e-mail Bridget Botelho, news writer. .

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