Outages can cause file system inconsistency and will result in a VM not fully booting.
This can be easily seen on the VM console during the boot process, like the image below.
To be able to boot up normally, you will need to run the file system check "fsck" using the following command.
This will run and will prompt to fix any inconsistencies found.
After the fsck program finishes run it a second time to confirm there is nothing else and then type "reboot" to restart the VM.