The lessons we learned at Christus Health about the successful use of virtualization can be categorized in the project life-cycle stages of planning, design, testing, migration, and transition to operations.
The time we spent planning paid off. Our assessment study allowed us to glean key information regarding our biggest opportunities regarding virtualization: payback and the ease to achieve the payback.
We took time to calculate and determine the optimum virtualization farm configuration with regard to cost and performance.
A key success factor was spending the appropriate amount of time in the lab validating study findings and assumptions on migration and application performance, as well as ensuring that there was a quick way to swing production systems back to physical hardware in the event of a performance issue in order to isolate and troubleshoot the environment.
Vendor application support is important. In the early stages of the project, we let a few vendors rattle our cages with statements regarding their lack of support for VMware. We ended up pushing the burden of proof back to the vendor to provide evidence of why it didn't support a virtualized environment. Most of the time, the vendor didn't have experience with virtualization, which gave us a good opportunity to prove the technology for it. After migrating more than 800 servers to the VMware farm, we have had only one issue that forced us to reverse the decision to virtualize the application.
Don't under- or overestimate the consolidation ratios that can be achieved. Conduct careful observation of application performance during testing and deployment and build flexibility into the deployment and migration plan to accommodate variances.
George Conklin is CIO, Mitch Lawrence is lead application analyst, and Mark Middleton is system director of IT architecture for Christus Health.