I'm trying to help expand a hard drive on our server's virtual machine, but I'm running into some trouble. When I tried to increase the hard drive size in the ESXi VM settings, I got an error saying "failed to reconfigure VM, invalid operation for device 3." I discovered that there's an old snapshot from about 3.5 years ago, and I've read online that snapshots can cause this type of error. Do I need to delete all snapshots to fix this? Are there any risks involved with deleting such an old snapshot?
5 Answers
If your VM is running, deleting that snapshot could take a very long time—possibly hours or even days. Once you start the process, don’t stop it! If you can afford to shut down the VM, that might speed things up a bit, but it will still be time-consuming, and you won’t be able to start the VM until it’s done.
It'll probably take several hours to delete the snapshot, so consider doing it on a Friday night and check back over the weekend. After expanding the disk, don’t forget to go into Windows Disk Management and extend the partition to include the newly allocated space!
How are your backups looking? It's generally safer to shut down the VM before deleting a snapshot, or even better, you might want to restore from a backup. Also, consider setting up some alerts or automation for snapshots that are older than 72 hours to prevent this from happening again.
You mentioned deleting "all" snapshots—do you have more than one? If so, I suggest deleting them one at a time, starting with the oldest. The nearer a snapshot is to your running system, the fewer changes there are to handle.
I've had to delete some pretty old snapshots before, like chains that were over four years old. It does take a long time, but there weren’t any significant issues. By the way, how big is the total space for the VM?
The total VM used space is around 700GB.