As others have noted, this is forcing amanda to do things she doesn't
want to do.  But still there are lots of benefits.

I'd solve this by having two amanda.conf files.  Almost the same, but
one set up to only do full backups (skip-incr IIRC) and one set up to
do only incrementals.

Then, I'd have a label regexp that admits both

SITE-FULL_000

and

SITE-INCR_000

(yes, use more digits than you think you need, so when you get new
tapes you can go from 000 to 009 to 010 to 019.  I'm now at 050
myself, in groups of 10.)

Then, have a cron job that copies in either amanda.conf.full or
amanda.conf.incr to amanda.conf before the dump runs.

Perhaps you can have tape labels different in each config too, so
amcheck will complain if you have the tapes backwards, but I'm not
sure.  Arguably amanda should only check labels at
amcheck/amdump/amlabel and not flip out if stored tape labels don't
match (e.g. from amadmin site find).

  From: Jon LaBadie <jon AT jgcomp DOT com>

  What are you looking for amanda to do for you that
  you could not do with cron entries and shell scripts?

With this (to answer Jon's query), you meet your imposed requirements,
and you still get multi-machine backups, holding disk, concurrency,
and the ability to find backups.  Making amanda do what you want is
vastly easier than writing your own scripts from scratch.

While I like the amanda way (I let it schedule, since my reqirements
are 'get data back if I have to' and all else flows from that....), it
actually would be nice if amanda supported more complex polices.
Someday I really need to find the CST to hook guile into amanda so
people can write their own 'planner' modules that meet arbirary
policies.

You may want to change the bump params to avoid level 2/3 backups,
which will tend to happen later in the week with the scheme you have
outlined, if you don't want that to happen.  But it's a fine thing to
actually happen, except that in your case your tapes are going to be
empty on incremental runs and you might as well stick to level 1s.

The real downside to this scheme is of course that you need a tape
bigger than the sum of all your (compressed) filesystems, but I
realize you know that.  But that's inherent in the requirements.

A softer way to do this would be to set dumpcycle to 7 days,
runspercycle to 5, and do a 'force' on everything before the 'full'
runs.  But amanda will promote some incrs to fulls on later dates to
balance things in that case, and you'd lose the dual-labels.

I haven't tried what I'm suggesting, but we do use dual configs.  The
noon config has no tape drive and a disklist containing only the
notebooks.  This dumps the notebooks to the holding disk so they get
flushed at night (since they are often missing at night).  The night
config has a full disklist - amanda won't flush dumps not in the
current disklist.

-- 
        Greg Troxel <gdt AT ir.bbn DOT com>