And what can't be virtualized these days? Applications get virtualized via service-oriented architecture (SOA) that can turn any desktop into a Citrix-like terminal. Virtual file servers are streamlining workgroup operations. And storage vendors still make a half-hearted attempt to sell the benefits of virtualized LUNs, even if customers can't come up with the same ROI figures as their VARs.
But let's look more closely at virtualized servers, or virtual machines (VMs) carved out of physical servers. In less than five years, VMs have proven themselves as a way to contain runaway server growth, while actually reducing the number of servers in a data center. It wasn't hard to see that most servers were running at well under 20 percent of capacity, leaving lots of idle or underused processing power. Then there's been a steady increase in power and cooling costs, and either smaller IT budgets or more controls where new spending was concerned. IT has had plenty of incentives to give VMs a whirl.
EMC subsidiary VMware remains the clear leader in this juggernaut of a market, commanding well above 80 percent of the virtual server business, according to most analyst estimates. How long it can fend off would-be rivals like IBM, Hewlett-Packard, and Microsoft -- in addition to smaller vendors like SWsoft or Xensource -- is anybody's guess. But despite what is likely to be a softer market for IT spending in 2008, Goldman Sachs pegs server virtualization as IT's second-largest spending priority after business intelligence.
The question of whether it's a good idea to virtualize servers has been settled. What data center professionals and storage experts are grappling with now is how best to deploy and manage VM technology. Byte and Switch spoke with users in a variety of industry sectors to get a feel for where the pitfalls are, and what customers wished they knew before they unplugged that first obsolete departmental server.