Veeam suddenly failed backing up one of my VMs, a VM homed at a datastore with multiple other VMs - these VMs were backed up just fine.
My first thought was that the device backing the datastore, an old piece of spinning rust, was about to fail. The S.M.A.R.T.-info from ESXi was no help. Zero errors and a interesting runtime of 42 hours?
Retrying the backup didn't help. This single VM still failed to be backed up.
I tried booting of a live Ubuntu ISO to run fsck and found some bad sectors on the volume. Surely the physical drive will be replaced, but for now the backup can run without errors.
Details:
fsck arguments: -ccfky
ESXi version: 7.0.0, 16324942
VMFS version: 6
Veeam VBR version: 10.0.1.4854