If you're an IT executive, chances are you're already thinking about storage virtualization. Nearly one-quarter of companies with at least 500 employees have deployed storage virtualization products already, and another 55 percent plan to do so within two years, according to a Gartner survey.

Storage virtualization is an abstraction that presents servers and applications a view of storage that is different from that of actual physical storage, typically by aggregating multiple storage devices and allowing them to be managed in one administrative console.

The technology is emerging fast onto the enterprise scene for good reasons: In many cases, it can reduce the management burdens associated with storage; and offer better models for datacenter migrations, back up and disaster recovery.

Enterasys Networks reaped these benefits rewcently when it moved a datacenter from Boston into its headquarters in Andover, Massachusetts. "In days gone by, before storage virtualization, that might have been an all-day, if not an all-week kind of process," says Trent Waterhouse, vice president of marketing, Enterasys. "Because of the storage virtualization technologies, the entire move happened in less than 30 minutes."

There are still common pitfalls that storage administrators should ponder, as well as questions they should ask before they roll out a storage-virtualization project. Here's a look at some of the top issues.

Managing Capacity

With storage virtualization, allocating storage is easy - perhaps too easy.

"You have the ability to affect more systems in the whole forest if you do something," says Jonathan Smith, CEO of ITonCommand, who cautions fellow IT shops to pay close attention to both the storage and performance needs of each application. "You just didn't have that power before. Now all of a sudden you can do whatever you want."

Smith, who is using LeftHand Networks virtualization on HP storage, says an IT pro might see a lot of empty space in a given storage volume and be tempted to fill it up. Overusing a resource, however, can decrease performance if the storage is allocated to a database or some other I/O-intensive application.

"Make sure you size it correctly and really understand how much horsepower [your applications need]," Smith says.

These concerns are especially true when it comes to thin provisioning, a component of virtualization technology that lets an IT administrator present an application with more storage capacity than is physically allocated to it. This eliminates the problem of storage over-provisioning, in which storage capacity is pre-allocated to applications but never used.

With thin provisioning, more than 100 percent of storage capacity can be allocated to applications, but capacity remains available because it won't be consumed all at once.

You can play it safe by allocating small volumes that never exceed the physical storage, or allocate as much as you want to each application, then monitor your systems closely, says Themis Tokkaris, systems engineer at Truly Nolen Pest Control. It's best if you can find a happy balance between those two extremes. "You have to monitor your pool so you don't run out of space, because that would really crash everything," Tokkaris says.

Related Articles

• Four Steps to A Business CIO
• Are You Ready for a Disaster?
• Data Backup: Keep it Secure
• Hole In Your Cloud
• Storage Virtualization: Boon or Bane?

Latest Articles

• The Quiet Threat: Cyber Spies are Already in your Systems
• Don't Wait for Adobe Sandboxing to Secure PDF Viewing
• Responding to Security Questions Successfully
• Security Secrets the Bad Guys Don't Want You to Know
• The 4 Tiers of a Secure B2B Framework