The parent virtual disk has been modified since the child was created

[OaktonIT]

Hi All-

I'm trying to find the source of this error. I understand the fix is KB 1004232 "Cannot power on a virtual machine because the virtual disk cannot be opened" and it has worked for us but why is this happening? I'm concerned because it's happened on 3 VMs in the past week and it seems to be a growing issue. TIA!

-Dan

[kjb007]

The only time this type of thing should occur is if you modify your config to use a base disk as opposed to the snapshot that your vm should be running.

This can also happen if you try to expand a vm's disk, when that vm has a snapshot on it. When you expand, if you expand the original disk, instead of the snapshot, then you've technically modified the base disk, but since your changes are written to a snapshot, then the CID chain gets out of sync. The safest thing to do is to commit/delete the snapshot before attempting to expand a vm disk.

-KjB

[OaktonIT]

Thanks. The explination makes sense but the situations don't apply. There have been no vm disk expansions or a reconfig of the disk on the VMs that are affected. I may have to open up an incident with VMware on this.