There are several methods to re-sizing virtual disks listed below. If you want to shrink the disk in ESX3 then using Vmware Converter is the best way to do this, you can no longer use vmkfstools to shrink a disk in ESX3, you can also try using QpartEd to shrink a disk. With all these methods you should make a backup copy of your original vmdk file in case something goes wrong. Also make sure you shutdown the OS cleanly before restarting the VM (GpartEd will sometimes fail otherwise). Methods 1, 4 & 5 are essentially the same using Linux boot CD’s and either GpartEd or QpartEd.