Virtualization Picks Up Steam

Tying together disparate disk systems in the data center is now taking on a new sense of urgency with the meteoric growth of server virtualization.

End users looking to achieve the true benefits of virtualization--the pooling of computing resources--are best served by holistically looking at both storage and servers. In turn, solution providers need to think in the same manner by developing the technical expertise and partnerships necessary to provide true system virtualization.

The imperatives to reduce costs and improve utilization and availability are driving the rapid proliferation of system-virtualization platforms from Microsoft, Virtual Iron, VMware and XenSource.

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Solution providers riding the wave of data-center consolidation should be looking at the storage-virtualization software options. Those who specialize in storage can grow their businesses by jumping onto the virtualization bandwagon.

Storage virtualization started to evolve well before server virtualization took off. There are numerous options for storage virtualization. The latest buzz these days is software that runs within the SAN switch. Other options include virtualization software that runs within the storage array, file virtualization and the use of specialty appliances. The latter approach, also known as in-band or shared-data-path storage virtualization, is the most widely adopted, mostly because it doesn't require server modifications.

DataCore and FalconStor are among those that offer in-band virtualization software. IBM also espouses in-band virtualization with its SAN Volume Controller (SVC).

In-band virtualization is old hat for quite a few storage specialists such as John Thome, a vice president at Cleveland-based solution provider Chi Corp. Storage virtualization never had the enterprise appeal system virtualization does. Demand for storage virtualization is a sheer necessity as a result of these rapidly growing server-consolidation efforts, Thome says.

"We're running into VMware everywhere, and as these people are looking into server virtualization, they are looking at better ways of allocating storage resources," says Thome, a longtime partner of FalconStor, whose IPStor allows customers to virtualize their storage systems.

Using the Java management console of IPStor, customers can view all storage resources as though they were one large SAN. IPStor lets customers provision software on an application server, such as a database or e-mail system. An end user can also make a disk array available to that application for a prescribed period and later add more capacity from another vendor's storage platform without having to touch the app, says Donald Mead, vice president of FalconStor's network-storage solutions.

NEXT: If virtualization platforms can consolidate servers and the networks and storage attached to them, why the plethora of storage-virtualization tools?

Indeed, the purpose of products like VMware's Infrastructure 3 is to allow organizations to run multiple applications on a server or cluster rather than requiring a separate host for every application. It allows applications to utilize multiple hosts as needed. VMware has raised the bar on server virtualization with its comprehensive resource-allocation tools, higher levels of availability and functions such as automated load-balancing. As companies virtualize their servers, consolidating storage and managing volumes of stored data is not cut-and-dry. Many small and midsize customers, as well as departments of larger enterprises, often rely on direct-attached storage, or DAS, rather than a SAN.

To get the benefits of true server virtualization, though, storage must be networked, says Aaron Schneider, director of services at Pinnacle Group, a Carlsbad, Calif.-based solution provider. "To get all the bells and whistles out of VMware, you need to have a SAN or some sort of centralized storage," Schneider says.

Building a SAN, however, could cost hundreds of thousands of dollars, a cost many companies simply can't afford.

"When people say they'd like to do server virtualization but don't have money to build a SAN, we direct them to storage virtualization," Schneider adds. In his case, the server-virtualization tool of choice is DataCore's SANSymphony software.

George Teixeira, DataCore's president and CEO, says partners working with his company, VMware and Citrix, can provide what he calls "total enterprise virtualization."

Customers who've bought into server virtualization or desktop virtualization using thin clients are typically open to expanding the scope of such projects. Hence, solution providers should partner with VMware, Virtual Iron or XenSource on the server side, Citrix or Provision Networks for thin-client virtualization and a storage software provider such as DataCore.

"What VMware does for servers and Citrix does for terminals, we do for storage," Teixeira says. Pointing out that VMware is on a run-rate to become a $1 billion-plus business for EMC this year, Teixeira says storage virtualization is a must for customers that are consolidating their servers.

"With server virtualization, it creates a double-edged sword because what you're doing is putting all your eggs in one basket," Teixeira says. "If you have a failure on that [virtual] server, you're taking down a bunch of systems." That's why, he says, it's important for companies to have a redundant SAN behind the virtual infrastructure--something VMware itself recommends. Yet many companies don't necessarily have SANs behind all of their systems--particularly small and midsize companies.

"The problem is that those kinds of SANs are hardware-intensive. We're talking about deployments that are hundreds of thousand of dollars and up," he says.

The key benefit of virtual environments like VMware Infrastructure 3 and Microsoft's Virtual Server is their support for iSCSI--meaning that storage can be connected within the data path on the Ethernet LAN or WAN. Conveniently, solutions from DataCore and FalconStor also support iSCSI. IBM doesn't support iSCSI, but rather Fibre Channel.

"We're not seeing a great deal of demand for [iSCSI] in our storage virtualization," argues Chris Saul, marketing manager for IBM's SVC product.

Although iSCSI has brought the price point for connectivity down, the automated fail-over capabilities are still embedded in the more expensive storage arrays to maintain the high-end functionality of a Hewlett-Packard Enterprise Virtual Array, Hitachi TagmaStore, EMC Symmetrix or IBM DS8000.

"Now you literally can create a complete environment for well under the cost of the SAN itself," DataCore's Teixeira says.