What is "downgrading a system"?

In Debian world, it means to move to an older distribution (typically, to move from [:DebianUnstable:unstable] to [:DebianTesting:testing]). Do not expect to get anything stable by downgrading!

Is it supported?

So, what's the supported way?

  1. Make a backup of your system before you upgrade, so you can restore your backup to "downgrade" it !
  2. or Re-install.

How to downgrade a system?

Be warned: you will be alone! However, Auke Jilderda wrote about the experience back in 2002: [http://people.debian.org/~osamu/pub/downgrade.html] (plus some comments from Osamu Aoki)