CIOs are always skeptical of ROI-driven initiatives that don't have hard cost savings associated--productivity gains that never materialize can haunt you for years. Virtualization does have measurable savings in power, space, and cooling, but it's difficult to pinpoint an exact tipping point where hardware and software costs are offset. So we asked Brad Krick, manager of technical support configurations at GreenPages, to provide some cost analysis.

Krick's assumptions: A company must replace 10 aging servers and their associated data storage. We specified standard Hewlett-Packard servers and VMware ESX enterprise licensing. We didn't add in the common components of all three: tape backup, Microsoft licenses, or installation. You would probably see lower initial installation costs to convert 10 physical servers to virtual versus migrating apps to new physical boxes.

Storage requirement: 500 GB of Tier 1 data, 500 GB of Tier 2 storage for disk backup (near-line archiving).

Scenarios under consideration:

1. Replace with 10 traditional servers: Ten HP ML350 boxes with mirrored boot drives and RAID 5 storage--$62,100.

2. Virtualize 10 servers using three physical servers with local storage: Three HP ML350s with more memory and RAID 5 storage running VMware ESX (licenses included)--$49,300.

3. Same virtualized servers in a cluster that boots to a 1-TB SAN: Three HP ML350s with more memory, boot drives, and VMware Enterprise, plus a Hitachi SAN for storage--$52,730.

Even companies leery of virtualization would be hard pressed to have IT spend $12,000 more for a traditional setup. But can you get the CFO to go $3,400 or so more for the third option? You should be able to win this point--the SAN addition increases costs, yes, but it opens up options for redundancy, snapshots, and thin provisioning. Don't let role lock-in stop you from broadening your virtualization plans to include a long-term storage strategy. You'll not only better leverage the full range of virtualization features, you'll end up with a higher-performing environment.

Michael Healey is chief technology officer of GreenPages Technology Solutions.
Write to him at mhealey@greenpages.com.

Photograph by Jupiterimages

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Analysis: Most Vital Part Of Virtualization May Be A SAN