Hello, the plugin works great as far as I test it with its options 
(last OMV and plugin version to date)
I would like to set it up so I can creat incremental backups, looking in man pages http://www.samba.org/ftp/rsync/rsync.html
Code
--backup-dir=DIR
In combination with the --backup option, this tells rsync to store all backups in the specified directory on the receiving side. This can be used for incremental backups. You can additionally specify a backup suffix using the --suffix option (otherwise the files backed up in the specified directory will keep their original filenames).
Note that if you specify a relative path, the backup directory will be relative to the destination directory, so you probably want to specify either an absolute path or a path that starts with "../". If an rsync daemon is the receiver, the backup dir cannot go outside the module's path hierarchy, so take extra care not to delete it or copy into it.--backup-dir=/media/mydisk/incrementaldir/$(date +%y%m%d%H%M)
I thought that option in Extra Options should do the work... but when I manually run the job the output window stays empty, seems not to work...
Is there a way to do this from Extra Options?
Thanks,