How is virtualization memory overhead calculated in the Consolidation Planning Module?

This article provides information regarding how the virtualization memory overhead is calculated in the Consolidation Planning Module of PowerRecon.

PowerRecon calculates the virtualization memory overhead by summing the total of the following:

1. A base factor to account for the host operating system
2. The percentage of total memory
3. A fixed memory value for each Virtual Machine

For example, if a machine has 1000 MB of memory with 2 Virtual Machines running on a VMware ESX Server then the overhead will be as follows:

200 MB + 3.5% x 1000 MB + 2 x 75 MB = 385 MB.

These values can be found in the \Program Files\PlateSpin PowerRecon <x.x> Server\web\Autonomic\Web.config file:

<add key="VMwareESX"     value="Processor|Percent=10, Memory|Base=200, Memory|Percent=3.5, Memory|VM=75, DiskSpace|Base=0"></add>
<add key="VMwareServer" value="Processor|Percent=25, Memory|Base=512, Memory|Percent=2,    Memory|VM=60, DiskSpace|Base=2"></add>
<add key="MicrosoftVS"    value="Processor|Percent=20, Memory|Base=512, Memory|Percent=2,   Memory|VM=60, DiskSpace|Base=2"></add>