I'm having an issue with my Synology DS210j, DSM 4.2-3211 version.
NAS LUN backup fail issues began occurring for some time, with different backup tasks failing.
Issue reported in logs for this job is: "The lun is being backed up by another user"
There is no second user or device which is accessing this target LUN. This is special iSCSI connection to this Synology device only.
WD My Passport 25E1 attached on USB, as this is the target for storing those backups.
Checked iSCSI connection was online and working. Service status also connected. But backups failed anyway.
I have decided to delete the existing backup task, and create it from scratch.
This seems to work. It worked when backup job was started manually.
What also happened was that on some other backup jobs, it failed also but with different error: "Backup failed because backup destination was running out of space or the connection to destination server was lost."
Neither of those issues were true, as there were plenty of space and connection was established.
Also, those errors were gone by itself when I recreated backup task.
It was needed to delete the task and delete old backup folders, and create new one with different name of the task and also with the folder on which backup will be stored.
And this worked for a time actually, but started failing again.
In logs those two are switching from time to time:
Any suggestions what are my options here?