[PVE-User] LV Not Available - could not open disk - no such file or directory

[Dietmar Maurer]

> What is worrying is
> 
> a) there is no effective way to back up a VM if you cannot mount the
> partition

The basic idea of backup is that you do the backup "before" you have
a data loss ...

You can still copy the whole disk and then try to do the 
restore your data with that copy (I would not touch the original disks).