Home user: write a script that copies it off onto another machine. Enterprise server: buy a tape drive and consider using a program like Arkeia, or writing some really good scripts.
See Craig's ArkeiaNotes.
(P.S. Back up your data.) Otherwise you might end up like this guy - warning contains bad words.
Veritas are cool. (They employ geek goddesses, though that's another story.) Their Backup Exec product for Windows is very nice, and even has a Linux agent that lets you back up remote Linux servers.
They have a document that tells you how to set it up, but because you run Debian, you're going to want to do things a bit differently.
Untar and install to /usr/local/bkupexec. Create an /etc/bkupexec directory and copy the agent.cfg from /usr/local/bkupexec into it.
Then, get the BackupExecAgentInitScript?, run
and you're away laughing.
2 pages link to BackupNotes:
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