today I found my urbackup server not runnning any more. The backup folders had runned out of disk space. In /var/log/urbackup.log I got the following messages:
2018-11-28 22:22:57: ERROR: Could not free space for image. NOT ENOUGH FREE SPACE.
2018-11-28 22:22:57: WARNING: Not enough free space.
and then repeating for 4 minutes:
2018-11-28 22:26:25: ERROR: Error while writing compressed data to file
2018-11-28 22:26:25: ERROR: Writing to file failed
2018-11-28 22:26:25: ERROR: Last error: 28
After that nothing more.
Server Version is 2.2.11
OS: Debian 9.6
Filesystem of backupfolder: Btrfs