rdiff-backup is a reverse incremental backup system that works like rsync by only sending changes to files. The benefit of rdiff-backup is that it keeps the current copy of each file plus reverse incrementals that allow a previous version of the file to be recreated. It also preserves all file permissions and ownerships. Installing To install rdiff-backup: Install Jac0's alternative firmware and set up ssh as per the instructions Download and install Python Download rdiff-backup.tar and copy it to your NAS200 Log into your NAS200 and untar the file in the root directory Setting Up There is no server side configuration required for rdiff-backup but it does require some trickery pokery to get around the idiosyncrasies of Linksys's firmware. The basic problem is that a user can be configured for access by ssh or ftp/web but not both at the same time. This is an issue because it means that backups made with rdiff-backup could only be accessed by the rdiff-backup client which defeats one of the benefits of rdiff-backup. There is a workaround though. The explanation is best by example. I have a server "holly" that I want to back up. First create a user in the Linksys web admin called "holly" with a personal folder. Now ssh into your NAS200 as root. Go to /etc and edit the passwd file with vi. Copy the line for the user "holly" and paste in a duplicate. Edit the second entry for "holly" and change the user name to "holly-backup". Leave the uid and gid numbers the same. Change the home directory to /harddisk/volume_1/data/holly and the login shell to /bin/sh. It should look something like this: Code: holly:sc/YJyfrdbEkA:2000:501::/home/user/holly:/dev/null1 holly-backup:sc/YJyfrdbEkA:2000:501::/harddisk/volume_1/data/holly:/bin/sh To make it possible to do unattended backups we need to configure dropbear to use public key authentication instead of passwords. You will need to have a public/private key pair already generated on your server. Go to /harddisk/volume_1/data/holly and create a directory called '.ssh'. Copy your public key to a new file called 'authorized_keys' in the .ssh directory. Correct file ownership and permissions are essential for this to work properly. Change the owner and group of authorized_keys, .ssh and holly files/directories to holly:holly. Change the permissions to remove group and other write access from those three files/directories as well. It should now be possible to ssh into the NAS200 box as holly-backup without having to enter a password. Using Backups are made with the command: rdiff-backup --remote-schema 'ssh %s /harddisk/volume_1/conf/bin/rdiff-backup --server' --create-full-path --print-statistics directory email@example.com::holly where directory is the directory to backup from and 192.168.1.2 is the address of your NAS200 box. The backup will be stored in a directory 'holly' under harddisk/volume_1/data/holly. See the rdiff-backup documentation for more details on excluding files. The beauty of rdiff-backup is that the latest version of every file is easily available by ftp'ing into the NAS200 using 'holly' as the username. Files can be also accessed using the Linksys web interface but an idiosyncrasy of the interface is that files must be group readable to accessible. Rdiff-backup preserves file permissions and therefore files that are not group readable on the source will not be accessible via the web. Previous versions of a file can be retrieved using the rdiff-backup recovery options.