Hi Brian, Eric, all,

Eric Siegerman wrote:

On Wed, Jan 14, 2004 at 03:33:02PM -0500, Brian Cuttler wrote:

I'm not sure its "planner", what component handles which order DLEs
are handled in ?

Planner and driver both contribute, I believe:
  - Planner offers a suggested ordering (e.g. it gives priority
    to a DLE that's overdue for a level 0)

  - Driver determines dynamically which dump(s) it can start at
    any given time, based on your "dumporder" amanda.conf
    parameter, the ordering suggested by planner, and on
    available resources -- holding disk space, network bandwidth,
    number of dumps already running on that client, etc.  (N.B.:
    Once a dump has been started, it runs flat-out; Amanda does
    no further throttling.)

Let me emphasize that "dumporder" thingy. The default is to have the
first 3 dumpers prefer partitions dumping in short time, any additional
ones to prefer partitions requiering long dump times. This typically
leads to what Brian experiences: small (fast dumping) partitions are
dumped first and then taped as soon as possible. Depending on the

many other small partitions in the meantime.

This default may be specified explicitely as
  dumporder = tttTTTTTTTTTTTTT...
meaning:
  dumper0   t   prefer partitions dumping in short time
  dumper1   t   prefer partitions dumping in short time
  dumper2   t   prefer partitions dumping in short time
  dumper3   T   prefer partitions dumping in long time
  dumper<N> T   prefer partitions dumping in long time

Thus, large partitions are typically dumped and taped late, but not
neccessarily last. For a visual impression of how Amanda operates with
'ttTTTTT...' go to

  http://www.osgev.de/other/amanda/index.html#dump_00_00004

and scroll up a little bit. You'll see the start of a backup session,
directly after the estimate phase. Notice dumper0 doing most of the
small patitions, dumper1 dumping mostly the somewhat larger partitions
and all other dumpers working on the large partitions. Scroll down
further to see ever longer dump times.

These decisions are made by the driver, which has control over available
server resources.

The planner's "generated schedule" (which respects, among others, the
importance of a backup) is considered by the driver, but the most
influencing factor seems to be that "dumporder".

regards

Georg
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