I use VMWare Server 1.x in the environment I had a problem with this evening. I was running WindowsXP in a VM, and I had run out of space on the C drive. I tried running vmware-vdiskmanager to increase the disk space, but after doing so, I could not boot. The error I received was "The parent virtual disk has been modified since the child was created". This entry describes the solution to this problem.