Exclusive: EMC goes virtual

One of Invista’s more interesting virtualization features is the ability to move a logical volume from one storage device to another without interrupting applications that are using that volume. With-out virtualization, moving a volume often means stopping the application, moving the volume, then restarting the application and changing it to look at the data’s new place. None of this is necessary with a virtual volume.

Free IT resource Virtualization Insights from Top Experts - Learn how virtualization gets real! Sponsored by Dell Free IT resource Try Sun servers, workstations and storage products free for 60-days. Sponsored by Sun Microsystems EMC Invista EMC, emc.com Excellent  8.7 criteria score weight Management 8 20% Performance 9 20% Scalability 9 20% Ease-of-use 9 10% Interoperability 9 10% Setup 8 10% Value 9 10% Cost: Starts at $140,000, including all hardware and software Platforms: AIX, HP-UX, Linux, Solaris, Windows, VMware Bottom Line: EMC enters the virtualization arena with a solution that runs on intelligent switches from major vendors and that integrates with most popular arrays. The combination promises to preserve customers' investments in fabric equipment and storage gears without sacrificing manageability, performance, and scalability. With Invista, EMC is dealing a hand that many customers will be happy to play, penny-pinching be damned. About our Reviews and Scoring Methodology

To simulate moving a volume while an app is running, I created a virtual volume from a Clariion storage element, assigned the volume to my host, and filled it with files. Among those files was a movie clip that I kept running.

Back at the Invista console, I clicked on the new volume and chose “move;” Invista asked me to choose a target location and a data rate for the move (allowing for either low network load or faster completion). The move went off without a hitch, and the movie clip never experienced a hiccup -- a good indication that even the most demanding application should not be affected in such a transfer.

Invista’s powerful virtualization simplifies some administrative tasks, such as moving data to a faster array, without painful disruptions to your business. This alone should justify the nontrivial investment needed to acquire Invista.

But there’s more. For example, you can clone a volume and create a constantly updated mirrored image that can be detached and assigned to a different task (development, data mining, backups, etc.) at any time.

Invista also has powerful features to create new virtual volumes and dynamically extend one that’s running out of space. For the latter to be useful, however, your server OS must be able to play along.

Preserving current data is another concern. Invista can import existing volumes into a virtualized environment without affecting the data. This is a must-have for a smooth and painless installation.

To mark the difference in performance, I measured the transfer rate with Iometer before and after importing the volume. Adding the nonvirtualized LUN to my Windows host, formatting a volume, and filling it with data was nothing new. After running Iometer and saving the test results, I added the LUN to the zone managed by Invista.

With the new zoning complete, I clicked the rescan button on the Invista GUI. The new LUN appeared immediately in the tree, and I was able to assign it to my server as a virtual volume. As expected, the data content of the volume was unaffected.

Running the same Iometer script on the imported volume showed no significant difference in transfer rate, compared with the test run on the nonvirtualized volume. This result was a sign that Invista’s off-band virtualization adds little or no latency to a SAN.

In the zone
After evaluating Invista, my only want is for better integration with EMC’s ControlCenter SRM software and other management tools. As it is now, you must switch management consoles when moving outside Invista, for example, to define a new LUN on a Clariion or Symmetrix array, or to change zoning. However, I wouldn’t be at all surprised to learn that EMC has already chalked that in for future releases.

Otherwise, Invista storage virtualization brings a much-needed breath of administrative fresh air to existing SANs. It’s not quite a free lunch, but it could be your most effective investment toward managing storage according to business needs rather than technical constraints.