We have a ubuntu 16.04 vm running on hyper-v (I believe on windows server 2012). It had like 3-4 snapshots. I was trying to export it but due to # of snapshots (which had been running for a long time) it was too large. I powered down the vm, deleted the snapshots (through the gui), saw that the vhdx files had merged, then exported it. I later powered on the vm and it failed to boot properly and displayed an error message that said there was kernel panic.
One thing we've done is we've booted the vm with ubuntu disk iso and we were able to successfully mount the old filesystem. It seems the files are all there. My boss suspects the bootloader is corrupt somehow so we're currently running fsck. If anyone has any other suggestions for saving the vm that would be great.
I was wondering, based on the above info, what could have possibly caused the issue? Deleting snapshots should be "safe" so there's probably gonna be some paranoia about deleting snapshots until we can figure out the reason.