JoJoGabor
Expert
Expert

I generally add on 10% for VMware overhead to include snapshots. Bearing in mind that snapshots should not exist for any length of time, but they will be used in any backup process and potentially if using Update Manager to patch VM OSes. You will have to consider the .vswp files but this should only be used if memory is overcommitted, plus you will get vmware.logs for each VM.

You may also want to consider the likelihood that you will want to increase the VMDK. For database, file or EMail systems I am often increasing the size of the VMDK, so add an extra bit to the VMFS for expansion, unless you can plan for this in advance