jonash
In my backup dir, there were a directory scheduled.running,
Where exactly did you see this backup dir, on the USB disk ? or on the hard disk (mount point) of sme server ?
....which probably was from an old cancelled run
It is from an unsuccessful or incompleted backup. The next time the backup job runs, it will recommence that scheduled backup from the point it was up to.
If the backup was already half done (say yesterday), and then stopped (for whatever reason) then only the second half of the backup will need to be done (say today).
The problem for you is that the backup seems to repeatedly stop each time it runs, for some reason yet to be determined.
Can you please confirm what you are trying to backup?
Is it a local sme server to a locally connected USB disk, and there is no backing up of workstations or remote sme server involved ?