I have a case where I configured a nightly backup job to a local device, that device being an external HDD.
The O/S is Kubuntu 18.04 -
When the user plugs in the drive, it has to be selected before being mounted. (KDE Plasma requires the user to select the discovered drive before it mounts it for you)
When mounted it is placed under /media/$username/drivelabel
When first configuring a job Veeam checks to see if this is a valid external location (as in if you try to browse to a location on the same drive it's backing up it won't let you).
However - once the setup is complete, if the user unplugs the ext HDD and then plugs it back in (or if the system is rebooted), the device hasn't been automounted back to that same location, but Veeam agent still continues with the next scehduled backup job.
This causes the OS drive (root partition) to fill up and break the system!
Please fix =)