Home > Why isn't server virtualisation saving us more?

Companies have rapidly adopted server virtualization over the past few years, but there are big differences in their use of the technology. Most companies are able to reduce server hardware spending, but many don't realize an ongoing reduction in management costs. Furthermore, not everyone sees the same level of savings on hardware. If you're not saving as much money as you'd hoped from your virtualization and consolidation efforts, you can learn from the best practices of the companies that are realizing huge savings. These companies run at least five times more virtual machines per physical host than other companies and use streamlined IT processes.

You're virtualising, but savings are less than you hoped

Consolidation of x86 servers through virtualisation has reduced capital expenditures, lowered electrical costs, and freed up expensive data center space. These are big savings, but many of them are one-time windfalls that fail to alter your ongoing cost of operations. You can do much better - you may be leaving money on the table with your virtualisation projects because you're:

Not aggressive enough with the ratio of virtual machines to physical host. Some virtualisation implementations fail to produce the expected savings because the cost per virtual machine (VM) it too high. This usually results from poor VM density and high hardware costs in shops that are too conservative with their deployments. For example, many companies break even with physical hardware after three VMs, but they only put a total of five onto a server ca[able of running 15 VMs. They could have provisioned 10 more VMs for no incremental cost. Instead, it will take two more virtualisation hosts to accommodate the overflow.

Networked to an expensive Fibre Channel storage area network (FC SAN). If you want the flexibility to move VMs between different physical hosts for high availability or for load balancing, your physical hosts must be networked to shared storage. In the past, VMware only supported FC SANs. So while you were saving money consolidation physical servers you were also spending thousands of dollars per FC port to network your servers to storage.

Slow to update legacy IT processes. Once a server is virtualised, you have the option of managing it pretty much like a regular server or taking advantage of your new capabilities to streamline management tasks. Many companies decide not to rock the boat with overhauling their processes, and not surprisingly their ongoing management costs remain the same - with some one-time savings associated with the initial provisioning.

By Galen Schreck - Forrester