On Wed, Feb 12, 2003 at 01:07:45PM -0800, John Oliver wrote:
> On Wed, Feb 12, 2003 at 02:11:50PM -0500, Joshua Baker-LePain wrote:
> > On Wed, 12 Feb 2003 at 12:17pm, Frank Smith wrote
> > 
> > > --On Wednesday, February 12, 2003 08:50:56 -0800 John Oliver <joliver AT 
> > > john-oliver DOT net> wrote:
> > > 
> > > > I'm still having a problem with one partition that amanda keeps trying
> > > > to do a level 0 backup for, and fails.  Why will it not back up this
> > > > partition all by itself, or with just a couple of other things?
> > > 
> > > Is it larger than the 18GB taper was able to write to tape?  Also, did
> > > all the output come from the same run, because taper claims it wrote 18GB
> > > when it hit EOT, but the stats only show writing 564MB.
> > 
> > That's correct, though.  Only 564MB made it to tape successfully.  The 
> > 18GB is that 564MB plus 17.5GB worth of hda2 that amanda wrote before it 
> > hit EOT.
> 
> I want to see if I understand this correctly... since my holdingdisk was
> only 2GB, and the filesystem in question is ~18-19GB, amanda was trying
> to write it directly to tape.  Further, I'm guessing that, because the
> data wasn't going through the holdingdisk, that that was precluding
> compression, which is why I was running out of space (since my drive is
> 20/40).
> 
> But, then... the drive is supposed to be compressing, isn't it?  Maybe
> I'm still confused... :-)

You will have to tell us if you are configured for none, software,
hardware, or both types of compression.

If you were configured for software compression, then what was sent
to the tape drive, even without the holding disk, had already passed
through gzip.  How much it "compressed" we have no idea.  Some of my
file systems only shrink 2 or 3 percent.  I should probably turn off
compression for them.  But I've been lazy.

If you are using both software and hardware, it is my experience that
the compressed data will be expanded 20 - 30% by the hardware compressor,
not further compressed.

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