I asked about the differences between the levels of backup and I got (sofar)
two different answers (thanks to you both), so I still do not know for sure:

Nicolas Ecarnot wrote:
> Level n backup is a backup where you save what has changed since the
> last level n backup. period.

Gertjan van Oosten wrote:
> A level N backup includes all files modified since the last level M
> backup where M < N.  So a level 1 backup includes all files changed
> since the last level 0 backup; a level 2 backup includes all files
> changed since the last level 1 backup (or if there was no such backup,
> it includes all files changed since the last level 0 backup), etc.
> A level 0 backup includes all files, period.

That are two different ways, the first I normally call INCREMENTAL, the
second I normally call DIFFERENTIAL. I prefer the second, because mostly you
will not need every tape, but only the first (full) and the last, and not all
others in between.

Some more questions:
- in theory you can get an infinite level (no limit) backup ?
- the more low-level backups you see (0 and 1), the better Amanda can
  handle the dumpcycle and tape capacity ? Or the other way round, Amanda
  will try to make as much level 0 backups as possible but based on the
  dumpcycle and capacity she will choose to do more level 1,2,3,4 backups
  in between ?

tia
Jeroen Heijungs
Het Muziektheater
Amsterdam