Recent research revealed that almost 25 percent of the physical servers and 30 percent of the virtual servers are actually zombies. These servers have had no activity over the course of the last six months. Several of the past research groups concentrated on the physical servers that had represented almost 20 to 30 percent of the zombie system. This time however virtual servers were also considered, as the usage and cost of maintenance have increased.

Such unused servers act as a security risk for the enterprises, as most of them are rarely maintained or patched. The unused zombie servers also cost a considerable amount of revenue as the enterprises have to pay the licensing fee for software and virtual server.

The Research paper was made by Jonathan Koomey, a research fellow at Stanford and Jon Taylor, a partner at Anthesis Group, a consulting firm. Both had looked over more than 16,000 servers in about 10 different data centers.

Jon Taylor in an interview said that “The cost of running a comatose depends on the age and whether the value has fully depreciated. In some cases, even the total value of the physical server can be realized. One of the easiest arguments that counter is the energy consumption of unused space.”

As large number of virtual servers fall in the category of comatose and the number seems to increase at an alarming rate. Enterprises are being forced to pay the licensing fee for both virtual server and software, draining the operational cost.