On Thu, Sep 23, 2004 at 08:19:55AM -0500, Ivan Petrovich wrote:
> 
> > If you use software compression however, amanda pipes the data through
> > gzip before writing to tape.  This has two advantages:  gzip does not
> > suffer from the "expand already compressed data" syndrome, and amanda
> > has an exact knowledge how much bytes to write on the tape.
> > The added accuracy greatly improves the planning capacities of amanda.
> > Amanda really likes to schedule using accurate numbers.
> 
> Paul,
> 
> The problem I have with using software compression is that it adds
> several hours to the "estimate phase." Am I doing something wrong? Does

Is this based on experience?  Tar with and without software compression
or dump with and without SW compression?

> Amanda run the gzip ones to get the output size before running gzip
> again when performing the actual dump?

It was my understanding, without looking at the code now, that the
past results of SW compression (saved in the infodir) were used
during the estimate phase.

Of course, tar or dump still must do its thing during estimate.

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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