Virtualization in a heterogeneous environment
Given that virtualization is designed to combine multiple storage devices, it's not immediately obvious why it makes sense to virtualize your storage if it all comes from a single vendor.
There are compelling reasons, however, says storage analyst Arun Taneja. "A lot of people think storage virtualization has a prerequisite of heterogeneity, that it only comes into play when storage from three companies is involved," he says. "I say, forget it, it has value even if you are stuck with a single vendor."
The storage market is more proprietary than just about any other IT space, and this creates problems even if you have just one storage vendor, Taneja says.
Say you're an EMC customer with two Symmetrix DMX boxes, and "you just want to combine the power of those two boxes and manage it as one," Taneja says. "[Without storage virtualization] you can't do it. That's how ridiculous the world of storage is."
This "ridiculous" level of exclusivity in the storage market obviously takes on a new dimension when you're managing storage from multiple vendors. That leads to the next issue.
Choosing a vendor
Enterprises' primary procurement dilemma is whether to purchase storage-virtualization products from a storage vendor or a third party.
If your true objective is flexibility, especially if you're planning major data migrations, a third party is the way to go, Taneja says. Such vendors as FalconStor Software and DataCore are capable of managing storage from multiple vendors simultaneously, whether they are EMC, HP, IBM or Hitachi.
Truly Nolen chose a third party, DataCore, even though the company uses only HP storage. The company evaluated virtualization vendors including HP, EMC, and Dell EqualLogic, but settled on DataCore because it was less expensive and offers the flexibility of using whichever hardware vendor it likes, Tokkaris says..
The major storage vendors promise to be able to manage a heterogeneous environment. Examples include IBM's SAN Volume Controller, NetApp's V-Series, and EMC's Invista. As a general rule, though, vendors support their own storage products first and others second, if at all.
"They always support their own systems first," Taneja says. "That means EMC's Invista supports DMXs and Clariions, and they might support some other foreign devices; but the support for foreign devices always lags, and support for foreign devices is always incomplete. The whole idea is don't support your enemies' boxes."
Peters predicts that as storage virtualization becomes more common, market pressure will force vendors to do a better job supporting their rivals' technology.