A few weeks ago, I began a series that puts the spotlight on enterprise users who are virtualizing x86 servers, but with technology other than VMware. There is no denying that VMware remains the dominant force in the x86 virtualization market, but this really is the year when alternatives to VMware will start getting more attention.

Probably not surprisingly, all the enterprise IT executives I spoke with began with VMware, and many still run it in some capacity, but they’re all now moving beyond VMware technology to try competing approaches. Check out the Q&A I did with a user of the open source Xen hypervisor here.

This week my focus is on SWsoft. Initially, SWsoft focused on hosting service providers, but in recent years it has been putting more focus on Virtuozzo, its enterprise product. SWsoft takes a different approach to virtualization than its competitors. Similar to Sun’s Solaris Containers, SWsoft virtualizes above the operating system so that multiple instances of an operating system can run on top of a single installed version.

VMware, Virtual Iron, Xen and Microsoft, on the other hand, enable multiple different operating systems to co-exist on a single physical server.

Earlier this year, I spoke with John Yanekian, director of network services at the National Association of Home Builders in Washington, D.C. The NAHB started with VMware early on, but about a year and a half ago it started running SWsoft in production. What follows is an edited transcript of my conversation with Yanekian. I’ll continue the Q&A in Part 2 on Thursday.

Mears: Why did you decide to virtualize your x86 systems initially?

Yanekian: Our server room was getting crowded with too many Microsoft servers that were very underutilized. We just kept adding server after server. We were running out of KVM ports. We were running out of power plugs. We were running out of server racks. We said, ‘This is not going to work. We need to virtualize.’ We brought in VMware, but it was just basically test and development.

Mears: Why did you start looking at SWsoft?

Yanekian: We wanted to expand our virtualization project and we looked at Microsoft Virtual Server, but the performance was unacceptable [for production]. At the same time, I had gotten an invitation and attended an SWsoft seminar and that prompted me to test their software. I’m not going to say we had a problem with VMware performance, but Virtuozzo was better in everything. Virtuozzo has the good and the bad and VMware has the good and the bad. With VMware, each environment can have a different OS, but that adds up to licensing costs. With SWsoft and Virtuozzo you have one OS level, but you don’t have to get an OS license for every virtual server you bring up. Plus the cost of the product itself was a factor in our decision. In the long run, the more virtual servers we have the more money we save in OS licensing and then just the cost savings on the Virtuozzo product itself [vs. VMware]. It paid itself off very fast.