Data Guard Systems, which president and founder Timothy Maliyil describes as being "like Salesforce.com for a specific niche," had been using 60 servers in a data center, plus another 60 servers for redundancy and backup to prevent any downtime. Those servers required 240 amps of power. And the Cambridge, Mass., company was faced with having to buy another 30 servers -- plus an additional 30 backup servers -- to handle the tripling in business it had experienced the previous year.

Instead, it moved in March to a SAN comprising EMC Clariion CX500 arrays totaling between 6TB and 7TB of storage from Dell and four Dell PowerEdge 6800 servers with dual-core processors.

The Dell servers run VMware to virtualize the company's older servers, and the entire SAN uses just 24 amps of power, Maliyil said -- a tenth of what was needed before. Virtualizing the servers also resulted in much higher utilization.

Because Data Guard was using three data centers -- in Boston, Denver and New York -- Maliyil saved US$20,000 a month in data center costs, money that primarily went for electricity. The SAN itself cost $150,000, and the servers and other incidentals another $75,000, for an overall price tag of $225,000.

"It paid for itself in a year," Maliyil said. "I'd rather spend money on hardware than on a data center."