In recent encounters, I've run into several IT managers who have reached their original goal in virtualizing the data center and were now resolved to go much further--in some cases seeking a 100% virtualized environment. To them, virtualization is a better way of managing computing--and once started, it's hard to stop. In one sense, it's addictive.

In a conversation with Kyle Maeda, assistant general IT manager of PACCAR, winner of the InformationWeek 500 Top Company award, said his firm has virtualized 70% of its Renton, Wash., data center and would strive to reach 100% by the end of the year.

Jerry Johnson, CIO of Pacific Northwest National Lab, said his organization didn't set out to virtualize 85%-90% of the data center, but has ended up there. When it did its initial assessment, it put database systems and data warehouses off limits. But at this stage it's operating its SQL server systems in VMware virtual machines, although it still leaves Oracle databases and its data warehouses un-virtualized. Johnson doesn't rule out moving to 95% virtualized; he doesn't anticipate getting to 100%.

Pat Gelsinger, president of EMC's core information infrastructure products unit, said his firm has virtualized 70% of its servers, and is now shooting for 100%. "Now we're getting into the hard stuff, Oracle applications, SAP applications ... We truly believe we're going to get to 100% virtualized," he said in an interview last month at VMworld.

Corporate Express, Australia's $1.2 billion office supply chain, boasted at the end of last year that it's 90% virtualized and headed for 100%.

That makes talking to Bill Hurley all the more interesting. He is CTO and executive VP of Westcon Group, a $3.5 billion switching, advanced networking, and security technology distributor that also does business under the names Comstor and Voda One. Hurley cites the difficulties in getting through the last phase, but he said his data center is now 100% virtualized.

Westcon had two data centers when he joined the company in April 2008, one near its Tarrytown, N.Y. headquarters, and a second outside London, running a total of 325 servers. Hurley knew he only needed one data center, and he consolidated around a managed service facility in Cincinnati. Then he contracted for a hot standby site, also run by Cincinnati Bell's technology solutions unit, a hundred miles away. Since the servers were kept running, Westcon developers use them for development and testing, but their primary function is to keep live virtual images of Westcon's production systems running.

Westcon has virtualized with VMware's vSphere and Site Recovery Manager. The hot standby site receives the same data feeds as the primary data center; Site Recovery Manager can failover production systems to the standby site to prevent a business interruption, Hurley said.

With that issue out of the way, Hurley then concentrated on consolidating 325 physical servers in two data centers down to 22 servers in the Cincinnati center. The servers are Cisco Unified Computing System blades, capable of running large numbers of virtual machines. Westcon prepared for the move by first virtualizing its servers in its two data centers. The move then became a process of transferring complex files over the wire instead of shipping servers from England and New York to Ohio.

Hurley said the Westcon IT staff was getting familiar with virtualization before he arrived. Some of the Westcon servers "were pretty long in the tooth. The engineering team was doing virtual machines on its own without telling anyone," Hurley recalled. Prior to virtualization, an old server would periodically fail and IT staff would have to be called out in the nighttime to get the applications up and running again.

"They hated getting up in the middle of the night to fix known, bad servers. They virtualized the applications so they could move them if the server went bad. It was a survival tactic so they could get more sleep," he recalled.

VMware's timing, its early entry into the virtualization market, had a lot to do with how Westcon became a VMware shop. "It was what they could get their hands on at the time. They started to learn it," he said.

By the latter half of 2009, it had become a goal to virtualize 60% of Westcon's applications in the new data center. It was a reachable goal for a company that was heavily based on x86 systems in the first place. It had no legacy mainframe and a limited number of HP Itanium systems running HP-UX apps. It rapidly reached 60% virtualization, its return on investment point--and kept going.

"We live and breathe by our ERP systems," said Hurley of Westcon's global distribution business. The firm has 2,500 employees in 30 countries, with only 125 based at company headquarters. Westcon is an Oracle database user and one of the drawbacks of being 100% virtualized is that Oracle doesn't like to support its applications or databases when they are inside another vendor's virtual machines.

"We don't have a lot of problems with Oracle, less than five in the 14 months that we've been running it in a virtualized environment. But we've had a small number of times where we've had to bring the system down and replicate an issue outside a virtual machine," he said, to convince Oracle technical support that there was a problem that didn't originate with VMware.

In the old data centers, ERP was based on Oracle's J.D. Edwards. Westcon made the decision to move the J.D. Edwards applications as VMs into the new data center, then migrate away from J.D. Edwards to SAP. SAP has certified that its ERP applications run reliably under VMware's ESX hypervisor. Given Oracle's touchiness over supporting virtualized systems, Westcon has decided to migrate its Oracle database systems to IBM's DB2 as well when it makes the SAP transition. Its new ERP systems are slated to go into production in March 2012, he said.

"We virtualized as much as we could before we moved applications into the consolidated data center. We got good at it. Some of our engineers could virtualize an application over the weekend and Monday morning none of the users knew that it had happened," he recalled.

Another issue: "In some instances we had to change an operating system to Linux. The application seemed to behave better if it was virtualized on Linux, instead of Windows Server," he said. Examples included Business Objects and WebFocus business intelligence applications, and Oracle database systems running under Windows.

But the new virtualized environment requires fewer system administrators to manage, saving on managed services expenses, lowered the cost of data center consolidation, and lowered electricity consumption in the new digs. Hurley said getting to 100% virtualized has saved Westcon $1.1 million over a two-year period. He now runs 350 virtual servers on the 22 UCS blades, with some blades hosting only 3-4 virtual machines and some hosting 25-30.

"We didn't go into this saying, let's get 100% virtualized," he recalls. It had a target of 60% to obtain a return on its virtualization investment, but then achieved 70% and 80%. The need to move servers into the Cincinnati data center was a big driver; it was easy to move the VMs compared to the risk of interrupted business and lost data of a physical move. "Laziness in this case was a driver," Hurley said.

The decision to migrate ERP to SAP and DB2 enabled Westcon to top off its virtualization effort with all servers virtualized. "When we started, our stretch goal was 80%. We ended up at 100%," he said.

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