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.
See TarNotes for information on backing up large amounts of data to more than one tape.
See also HowToExt2fsUndeletion? (although you don't need to since you have good backups, right?)
2 pages link to BackupNotes:
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