SANs and virtual machines are a natural pairing. An eight-core server with 32GB of RAM now costs only a few thousand dollars, and that one box can run a handful of virtual machines effortlessly. Pairing a single computer with a storage area network, you can easily create all the services of a larger data center.
To install a SAN, you'll need a storage area network array with at least two drives, one or two additional network cards per server (two is preferable), an ethernet switch (again, a pair is better), and all of the associated cabling. It is technically feasible to use your existing network for your SAN, but in practice you would never want to. Though iSCSI is a reduced-overhead protocol, subjecting your network to both iSCSI and regular ethernet traffic would quickly flood it .
SAN technology lets you store data across multiple servers with a level of efficiency unmatched by traditional options. A SAN can reduce the number of hard disks by 50% or more, which saves money in several ways. Fewer drives use less power, obviously, but they also generate less heat, reducing expenses for cooling systems.
There is a learning curve, in addition to additional upfront costs, but the payoff is the need for fewer disks down the road, less administrative overhead, and lower energy costs.
Michael Scalisi is an IT manager based in Alameda, California.