I found just this:
8.1.12 Automatically backup UrBackup database
If checked UrBackup will save a backup of its internal database in a subdirectory called ’urbackup’ in the backup storage path. This backup is done daily within the clean up time window. Default: Checked. If you backup a lot of files and the database gets large consider disabling this and performing the database backup via another method, e.g. by installing the UrBackup client on the server. You should backup “/var/urbackup” or “C:\Program files\UrBackupServer\urbackup”.
but I don’t see any info about /home/urbackup/urbackup . Files into this directory look like similar.