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"EMC and Compaq are implementing virtual technology at the controller level. That's a logical level to do it," Jacobs says. "What I don't like about the Compaq and EMC solutions is that I'm locked into a single vendor for my storage."
Jacobs manages a 9TB storage area network (SAN) built on EMC Clariion and Dell Power Vault boxes, sharing identical architecture for worry-free interoperability. He says EMC has been "knocking my door down for two years now," but he opted to test a solution from StoreAge Networking Technologies. StoreAge offered him a cost-effective solution, compatible with as many as 20 other vendors.
"I think virtualization is a very proprietary thing," SNIA's Skardal says. "Companies say they do virtualization and do some level of integration or hiding, but the solutions are still very proprietary. "The next leg is to start using the existing standards more and more," he says.
In fact, interoperability is one of the most pressing issues facing storage virtualization firms today, says Anders Lofgren, senior industry analyst at Giga Information Group. "There has to be a whole lot of cooperation with a lot of different vendors for it to work flawlessly."
One IT manager, who wanted to remain nameless, oversees a significant storage virtualization build-out for a U.S. government research facility, and says anything less than flawless invites disaster. "It all comes down to product maturity and interoperability. Especially when you are booting
The challenge for managers is that storage virtualization solutions can present a single point of failure. The government IT manager complains virtualization solutions lack maturity for such a mission critical role, making it difficult to set up, for example, redundant servers in an active-active configuration for instant failover.
One way to achieve that interoperability is through standards. Today, solutions supporting multiple vendor storage subsystems do so only because the developer has written code specific to each product. An established standard would allow companies to source storage from multiple vendors and be assured of interoperability with their virtualization solution.
The SNIA has attempted to rally a standard around the Common Information Model (CIM), but Skardal says those efforts have failed to gain much traction until recently.
"There's been considerable effort at the SNIA to get CIM going and it has petered out several times. The main reason for the lack of success is that CIM encourages vendors to model their solution down to the finest detail," Skardal says. "There's been some excitement about CIM, but I keep seeing so much complexity coming up. It becomes very difficult to reconcile [vendor] models into a standard model that you can write interoperable software against."
Still, Skardal and Tanner agree that the CIM standards effort is gaining speed. While that momentum should allow IT managers to adopt virtualization with greater confidence, questions still remain.
Aenta's Pomposi isn't that optimistic. "You have all these standards where the protocol is well defined, but the manufacturers of components that plug into these protocols many times will not support other vendors' equipment within that framework," he says. "What an organization like Aetna runs into is that the minute you plug disparate devices into that network - I'm talking Fibre Channel - the support structure goes out the window. In other words, if I throw a product in there, does that mean EMC will no longer support their solution?"
Another issue that concerns IT managers is storage management. Bob MacDougal of Canada Tire is looking closely at moving to a virtualized storage solution. As senior team leader of storage management, MacDougal worries that any virtualization solution his team adopts might end up hurting management capabilities.
"My concern is that even with virtualization, there is going to be some software tools that each vendor are going to have that are proprietary and they won't share with other vendors. They are not going to give away the proprietary stuff," MacDougal says. "When you want to really drill down at the disk level and the different software levels, I think there is still going to be some dedicated software out there."
ChoicePoint's Jacobs has similar concerns. While physical changes to hardware are rare in his infrastructure, the StoreAge software offers no ability to manage hardware directly.
Akhbar Tajudeen, Director of IT at Alloy Inc., New York, NY, a demographic marketing firm, says he'd like to see management software moved up the list of priorities by vendors. His experience with a FalconStor IPStore appliance-based virtualization has been positive, enabling him to streamline access to a 1.2TB data store. But it's clear that the management component of the solution needs honing.
"Hardware vendors know RAID technology and Fibre Channel and those sorts of things, but they are not dealing with the issues that an IT manager might be more concerned with," Tajudeen says.
Tajudeen brings up a serious issue that critical storage management capabilities such as replication, mirroring, time mark and snapshot are currently implemented at the array level. IT managers who move to virtualization solutions in heterogeneous environments find they are giving away functionality to achieve the convenience of unifying storage devices. The trade-off - both in terms of capability and integration challenges - is significant.
Cadence Design Systems, San Jose, CA, a leading maker of engineering software, deployed Veritas software to help reign in 100TB of data spread across both a SAN and network-attached storage (NAS) device. Mike Forman, director of IT, North American Operations, says Veritas was one of the only solutions that could unify both types of storage. Today, their Veritas software runs on clustered Sun servers and acts as a gateway to NAS- and a SAN-based on an IBM ESS disk array.
Forman says the solution has worked well after an intensive deployment period, but that his team would like to see better management tools.
"I think there are some OK [SAN management] products out there, but they are not quite there yet. In our assessment, we think it is going to be another six months to a year before we have some really good SAN and storage management products out there," Forman says.
In fact, Forman's software-based approach offers access to one of the more mature management solutions on the virtualization market. Veritas' clustering and volume management software, for instance, are widely deployed solutions. But are managers ready to ditch their existing solution set and accept the prospect of introducing a performance bottleneck?
Pomposi believes that's a decision each manager has to make. "In a heterogeneous environment there are going to be some trade-offs," he says. "The big question, of course, is how many of those trade-offs are you willing to take? For myself, I'm willing to take a whole lot of trade-offs."
Taking the plunge
Like many IT managers, MacDougal says his company won't deploy a storage virtualization solution until it has seen other similar outfits make the transition. Nonetheless, he's busy preparing his infrastructure for the transition. Canada Tire currently runs an EMC-based SAN with a McData switch, but MacDougal hopes that will change.
"Our intent is to have a virtualized storage concept, so if we do put a Hitachi box in there, nothing is going to change," MacDougal says. "When we first started talking about SANs two or three years ago, we always knew virtualization would come. There's no doubt in my mind this is going to go and it's just a matter of how quickly and how well it is going to get accepted."
Other companies are making the move ahead. At Cadence, storage virtualization has enabled the company to unify both SAN- and NAS-based storage to let the company keep up with storage demands that double yearly. Demographic marketing firm Alloy also took the plunge, deploying FalconStor IPStore appliance-based virtualization for its 1.2TB build-out. "The solution helped cut the time to assign storage from several days to several hours," says Tajudeen.
Clearly, companies are successfully deploying storage virtualization solutions. But for most IT managers, the question remains open: Is storage virtualization a reality?
"If you had asked that question nine months ago, I would have said that it was all fluff," says Pomposi. But looking ahead, he adds, "During the next 18 months there's going to be an emergence of products and technologies that will make this technology real for more and more companies."
This was first published in June 2002