ReadyNAS RN314, OS 6.1.2 backup loop?

What is the USB drive being filled up with?
If you start with an empty drive, does the first backup complete without filling up the drive?
Are you backing up 1 share?
Can you post your backup settings?

I´m backup-ing the entire NAS. I cant seem to find any spesific files, only user folders at the external harddrive after backing up.
This is an external harddrive i backup to once in a while, and then place it on an remote location.

Here are some screenshots.

Are you sure the USB drive was properly ejected the last time you used it? Maybe try reformatting it.

I have tried reformatting the drive several times, deleting the backup job, and recreated it with no luck.

Do you have snapshots on the source?
Perhaps setup backup jobs for each share rather than the whole volume.

This exact thing is happening to me. When I pulled the usb drive and looked at it's contents it was clear it was copying the snapshots as well.

It seems that if you backup at the volume level this includes the snapshots. It's too bad that there is no "all shares" selection. Does this mean that I need to schedule a separate backup job for each non-home share? Ugh. Is there no way to have multiple shares in a single backup job?

If you backup at the share level snapshots will also be included unless you use rsync for backup and specifically add the snapshot folder to the exclusion list.
It is possible to use rsync to backup to a usb disk.

There isn't an option to have multiple shares in a single job.
Unless you have a very large number of shares, setting up a job for each share is not that onerous and of course you only need to do it once. It allows you to to be specific about exclusions (like snapshot folders and recycle bins).