On Fri, Oct 17, 2003 at 11:18:48AM +0200, JC Simonetti wrote:
> I have different values for the filemarks, measured with another program
> and not amtapetype.
> 
> 
> On Fri, 17 Oct 2003 10:54:11 +0200
> Paul Bijnens <paul.bijnens AT xplanation DOT com> wrote:
> 
> > Or, your could use a good conservative approximation like:
> > 
> > define tapetype DDS3 {
> >      comment "DDS3 tape drives"
> >      length 11500 mbytes
> >      filemark 111 kbytes
> >      speed 2500 kbytes
> > }
> > 

Regarding the filemark, I personally think we place too much importance
on its magnitude.  Paul indicated later that this was a "composed" tapetype,
not measured.  But some might think that looks like a big number, a lot of
wasted space.  Try to put some numbers on it:

I don't get more than 20 - 40 DLE's on a single tape.  I suspect that is
pretty common, certainly I suspect few would routinely put 100 DLE's on
a single tape.  Yet even given this many "filemarks" wasting space on
the tape, 100 * 111KB is 11MB.  With a total tape length of 11GB, 11MB
"wasted" is a tiny 0.1% of the tape capacity.

The sermon is, unless you see really ridiculous filemark values,
don't worry.  They have nearly zero impact on amanda planning.

I probably should have included another "I think" on that last sentence :))
But I'll chance it.

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