Virtualization drives advances in storage management

The convergence of server and storage management is slowly taking place as enterprises look for more automated ways of managing their data center assets. Spurring the trend toward convergence — which remains somewhat hampered by a lack of available tools — is virtualization technology.

“If you don’t believe servers and storage have converged, all you need to do is take a look at server and storage virtualization," says Greg Schulz, senior analyst for Storage IO. “Let’s go way back — originally servers and storage were managed together, then they were separated, and now they are being put back together again."

Virtualization technology lets administrators divide physical servers or storage devices into logical virtual machines that can support different operating systems and applications.

Businesses are looking to virtualization so they can consolidate server and storage resources; run multiple workloads on a single machine more efficiently; and dynamically provision resources as application and business needs shift.

Server virtualization software from companies such as VMware, SWsoft, Virtual Iron and XenSource has been adopted by leagues of users; according to IDC, more than three-quarters of companies with 500 or more employees use virtual servers, and 45% of all new servers purchased in 2006 were virtualized.

However storage virtualization deployments are less mainstream. IDC reports 49% of companies are evaluating storage virtualization, while 34% have implemented virtualization software or hardware. Enterprises are having difficulty adopting storage virtualization products to pool resources from multiple heterogeneous arrays because the software to do it is lacking.

Where the gaps are

When businesses deploy software for creating and managing virtual servers, the virtual machines typically get storage capacity from shared storage networks. Most link to Fibre Channel and IP storage-area networks (SAN) or network-attached storage devices — not direct server-attached storage. According to host bus adapter vendor Emulex, at least 70% of VMware ESX Server users get their storage from SANs.