Hy, I've tryed to migrate some VM from my 3.5i environment to a brand new vSphere 4.0 U1. The two platforms are running simultaneously, sharing the same SAN. I Migrate my VM by stopping it, unregistering in vcenter (esx ver. 3.5, i call it esx3), register in vSphere (esx ver. 4, i call it esx4), and migrate upgrade virtual hardware before powering it up (First mistake). vMotion was enabled on esx4, seem to be a second mistake. After a day or so, i encountred problems joigning the esx server (esx4) and decided to unregister my server for esx4 and fallback to esx3. esx3 refused to boot, i supposed this was due to virtual hardware in Version 7 so i recreated a new VM pointing to the vmdk of the old VM. Everithing seemed fine until i log into the server and discover that i was running on the original disk ith every snapshots ignored even those created on esx3. I tried to reboot VM on esx4 but VM doesn't power up because "The parent virtual disk has been modified since the child was created". I've got a copy of a later state of the drive but generated between two snapshots (ovf generated with canverter standalone) as a backup. Do i have a chance to recover at least some files on the virtual drive or (as i tink) all is played, i've done enought mistakes for this time. Thanks for your help.