We all know that hardware and memory are crucial to virtual machines, but when a VM crashes is it the Virtual Machine it self or is the underlaying hardware the source of the problem. This is one of the reasons that before an host is taken into production it is recommended to do a 3 day memory test. Go and ask your self have you done this ? You might run into problems. To eleviate these hardware problems VMware released 2 new documents: Validating host memory and Performing hardware diagnostics. Both documents contains links to usefull hardware diagnostic programs.