Not a lot of companies have virtualized their storage, since they don’t understand what it’s all about, or they don’t see a compelling reason to do so.
CASE STUDY: Memory Sizing for Server Virtualization.
Server virtualization is a much easier sell, since it’s driven around consolidation, with tangible cost savings. Storage virtualization, on the other hand, is really about getting longer life out of storage assets. For companies considering a virtual storage environment, it’s less about capacity and more about the complexity of the
infrastructure.
And the cost savings are not as clear-cut as server virtualization, said Jason Bremner, director of research for Canadian infrastructure hardware with IDC Canada. Where you could see some cost savings is in better utilization of storage capacity. Once you take your storage out of the confines of attached storage, you’re making it more usable for more applications and more customers, but you’re also protecting it by having a redundant environment. It takes time for IT staff to allocate and deploy storage capacity, said Bremner. See also Canadian Space Agency explores virtualization
Unstructured data is driving additional storage capacity needs, and many organizations don’t have formal guidelines around that. And it’s difficult for an IT manager to go to the management of a small company and tell them they only get 50MB of storage – or enough for about 250 e-mails.
“Storage virtualization can help with that as long as it’s seamless to the end-user,” he said.
In a recent IDC survey of Canadian firms with more than 500 employees, 23 per cent of respondents said they’re using storage virtualization. Only only six per cent of medium-size firms (with 100 to 499 employees) responding to the survey said they were. About equal numbers of medium and large firms plan to adopt it in the next year.
But there are still large numbers that aren’t adopting storage virtualization – 76 per cent of medium firms and 74 per cent of large firms say they don’t see a need for it.
“[IT executives] really need to figure out what benefits they’re going to get from this,” said Bremner. “They have to sell it internally because as much as it makes sense, it’s probably not as clear-cut as server virtualization.”
Even though it’s been around for a few years, it’s still confusing, so some education needs to take place. Potential benefits include business continuity and compliance with accounting regulations. Look at how storage virtualization technologies map into what you already have. Also, look at different vendors, and which technologies you’re betting on to be around for the next couple of years.
Virtualization is really focused on removing some of the complexities of the information infrastructure itself, not necessarily the management of those objects, which are more tightly coupled to the business application, said Doc Derrico, vice-president of infrastructure software with EMC. When EMC entered the storage virtualization realm, it was targeting that management problem, but found customers were really trying to solve a much more pressing problem: data mobility.
The most prevalent reason for virtualizing a storage environment, said Derrico, is to upgrade to the latest technology or to move data centres. Data mobility also helps solve the problem of information lifecycle management (ILM), as information continues to grow and expand. Companies are looking for ways to continue to keep that information online and available, but without paying a higher price for tier-one storage. While volume management is a driver, it seems to be coming into play post-deployment.
Storage virtualization isn’t for everybody. Look at how big and complex your environment is today, said Derrico, and where it’s heading in the future. How often do you envision moving information assets around the infrastructure? If the business is dynamic, growing, or has an unpredictable workload, it makes more sense to move to a virtualized environment.
So how does it work? Virtualization is a logical representation of resources, not constrained by the physical limitations of the devices underneath, said John Cardoulis, brand manager of IBM System Storage with IBM Canada. It adds or integrates new functions with existing services and can be applied to multiple layers of an IT infrastructure.
IBM approaches storage virtualization as a way to help manage the different numbers and types of disk subsystems on the floor of a data centre. Customers often deploy several different disk subsystems, to which there are several servers attached.
“You end up with little islands of storage that are difficult to utilize,” said Cardoulis. “Quite often we’re paying for that disk but not using it.”
A virtual interface provides visibility into all of the storage out there, and it’s easy to get to, carve up and use – helping to reduce the cost and complexity of managing that storage. It also allows the IT manager to create different tiers of storage. “ILM is a concept of practices and architecture,” said Cardoulis. “You need to put the right data on the right media at the right time.”
The benefits have to outweigh any changes you’re going to introduce into your environment, said Sean Derrington, director of product marketing with Symantec’s SSMG Division. There’s a difference between going back and redeploying a capability on existing systems versus a go-forward approach. It’s also important to take server virtualization into account. Once you’re running multiple applications on the same server hardware platform, you’re increasing the utilization of servers – but you’re also creating storage management complexities.
If you’re looking at server virtualization, is that going to increase your storage management complexity, and is that worth doing?
“Oftentimes the answer is yes,” said Derrington, “but you want to be able to manage your storage the same way in a physical and virtual server environment.”