I assume you used the VMWare Converter P2V tool to move your servers, which works very well for Windows and not as well for Linux. VMWare Converter fiddles with the underlying Windows configuration so the image will work well on VMWare.
If you had used a Linux cloning tool, such as Clonezilla, you probably would have had a different experience. Of course, some older distros such as RHEL4/CentOS4 also did stupid things like the initrd would only contain the SCSI driver it needs to boot on specific hardware. Sometimes you would have to go back to the original hardware and tell it to store/load the SCSI driver for VMWare.
Sometimes it pays to have better sys-admins.