Managing Virtual Storage on Your SAN

IT managers have a lot more motivation when it comes to keeping their storage area networks, or SANs, up and running. More and more data is being stored on these virtualized networks, and they continue to be popular. In a survey conducted of 388 executives in December 2008 for SHARE, an association of corporate users of technology, storage virtualization was under way at half of respondents’ companies. However, management was still a challenge, and many of the implementations were at departmental, rather than enterprise, levels.

So what can you do to keep your SAN properly maintained? Here are several best practices:

Understand how much effective storage you really have. Just because you have a terabyte disk doesn’t mean that much space is really available: After you set up RAID groups and subtract overhead by your SAN solution, it might be a lot less. So take advantage of deduplication software tools to further reduce storage needs.

Also, if you plan on using virtual servers with your SAN, keep in mind that “it is very easy to consume disk space very quickly because you can easily copy new virtual machines,” says James Sokol, the CTO for Segal, a benefits consultancy in New York. Sokol suggests doing a periodic audit to determine which virtual servers are really needed for testing and operations.

Organic Valley, a large organic farming cooperative based in La Farge, Wis., uses two NetApp SANs holding 10 terabytes each. It was able to save more than $500,000 in capital and maintenance costs by implementing various space-saving technologies and being careful about storing duplicate data on its SANs.

“We were able to remove a lot of duplicate data and saw 20 percent to 50 percent savings in some of our volumes as a result because we make use of virtual servers that are running the same configurations,” says George Neill, Organic Valley’s IT director.

Consider how your disaster recovery needs will influence your SAN configuration. Organic Valley has used its SANs to run a disaster recovery center at another location 30 miles from its headquarters. “If we had had a better idea of what our retention policies and recovery time objectives were before we started, we would have seen an even greater benefit from our SANs,” Neill says. “You really must understand which of your applications need which levels of recovery in your production systems.”