My old (well, almost two years old at least) external hard disk stopped responding, and it looks like its the time to find another backup solution. Since I have a small, personal server running Ubuntu, regular full system mirrors on an external USB 2.0 hard disk should be enough, but I also need to learn more about the various backup procedures. Here are couple of links to pages that I should probably read with care: “Backing Up Ubuntu“, “Howto: Backup and restore your system“. Any further resources are also most welcome.
frans goes blog 
Making a tar package of the whole system is not the most efficient way to go in the long run — you’ll basically have a non-updateable backup of the situation at one time, and need to start from the beginning when starting a new backup.
A simple, efficient, and free program for taking continuous, incremental backups and having multiple backup sets without them all requiring disc space for the whole backup is rsnapshot. See http://www.rsnapshot.org/
Looks great — many thanks Tero!
I have now tried to set up rsnapshot for some time, but it looks like the command prompt interface and syntax based configuration is not for me. I have now set up SimpleBackupSuite which is easier for me to approach with its graphical user interface:
https://help.ubuntu.com/community/BackupYourSystem/SimpleBackupSuite