You may want to install rdiffWeb to manage the rdiff backups created by the python program rdiff-backup that you have installed with ipkg. The advantage of rdiffweb is that it gives your users a nice web interface for restoring files on their own, without administrator intervention.
Unfortunately rdiffweb is not available from ipkg. rdiffweb requires the following software packages to be installed: Python, librsync, rdiff-backup, CherryPy. The website lists pysqlite as a requirement as well, however, in Python 2.5+, the sqlite3 is included in the distribution
There are a few directories that rdiff-backup needs to work.
You should create a share for your rdiff backups using the web interface, which is stored on the volumes of your choosing. /usr/share/rdiffbackup/
*Work in progress*