Hi Uroni, something else I noticed, but I don’t have logs to back my story up.
First point:
I have a machine with symbolic links in the backup location that points to very large folders (time machine backup folders) outside the backup location. Even with the symbolic links set as excluded in the backup location settings, the indexing will try to index the very large time machine Backup folders. For some reason the indexing never finished. The only way to get it to backup was to delete the symbolic links
Second point:
after the initial full file backup, I recreated the link, thinking the issue might only have been with the initial file indexing. I let urbackup do its think for a couple of days, until I got warnings my backup space was low. For some reason, I think that the attempted backup of the time machine folders caused the server to write large amounts of temporary files.
I realise this is not much information to go on, especially point 2. Point 1 is pretty clear though I hope.
Thanks for this brilliant backup system !