Re: streaming fixed?

  Instead, it says, if a backup is level 0, can it be buffered on
  the holding disk.  If the reserve parameter is set to 100, then
  100% of the holding disk space can be used only for incrementals.
  All level 0's will go straight to tape.  If the reserve is set to
  25%, then that portion can only be used to buffer incrementals
  while the other 75% of the holding disk can be used for either
  level 0's or incrementals as needed.

$(prefix)/share/amanda/WHATS.NEW says that this applies only in
degraded mode.  Before I put in 'reserve 50' I was seeing level 0s on
holding disk, but amanda would not _start_ any level 0s if the tape
was missing or had failed.

I do something similar to Glenn, but for a different reason.   I do
'archive' runs on the weekend to holding disk, and flush them during
the day on Monday.  This avoids backing up active filesystems (and the
slowness from that), and the tape drive is idle then.  I set reserve
to 0 so I can use the whole holding disk - each week does 10G of level
0s, with skip-incr.

Quoting the docs:

* LEVEL-0 DUMPS ALLOWED WITH NO TAPE

If there is no tape present (or the tape drive fails during dumping),
Amanda switches to degraded mode.  In degraded mode, level-0 dumps
are not allowed.  This can be a pain for unattended sites over the
weekend (especially when there is a large holding disk that can hold
any necessary dumps).  Amanda now supports a new configuration file
directive, "reserve".  This tells Amanda to reserve that percentage
of total holding disk space for degraded mode dumps.  Example: your
total holding disk space adds up to 8.4GB.  If you specify a reserve
of 50, 4.2GB (50%) of the holding disk space will be allowed to be
used for regular dumps, but if that limit is hit, Amanda will switch
to degraded dumps.  For backward compatibility, if no 'reserve' keyword
is present, 100 will be assumed (e.g. never do full dumps if degraded
mode is in effect).  NOTE: this percentage applies from run to run, so,
as in the previous example, when Amanda runs the next day, if there is
3.8GB left on the holding disk, 1.9GB will be reserved for degraded
mode dumps (e.g. the percentage keeps sliding).

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