As i see it, amanda is supposed to do backups and let her stick to it.
It is said that if something fits all, it fits none, meaning that if you
put too much features (and too different) into one system, then it tends
to take more time to work around the problems, than to develop a unique
solution for your needs.

I think that most of the users think all of their data is valuable or
more or less devideable between disks depending on the value (therefore
configurable to take on different backup stragegies)

So you could offer them different strategies for every one of their disks
(servers, etc) and leave it up to them to decide what strategy they want
to use to back up every disk.

This way you have to configure disklist file, according to the demands of
customers - that's what you have to do anyway, as amanda disklist
configures a disk to be backed up with a single and independent (!)
dumptype.
So your first (partial) plan wouldn't hold anyway,
because that one would have calculated quatas for every disk separately
and (without any groups) it wouldn't do you any good.

But what could be done (IMHO) very easely, is a separate program, say
amquata, that analyzes amanda logs and digs the info from there, how much
quata one uses, and when the limit is exceeded, it can inform the person
responsible (and possibly do much more).
This way no changes are made to the existing system (except the adding of
the amquata program and its configure files) and it will be backwards
compatible as well.


best,
Laas Toom