At 17:39 04.04.2007, Jon LaBadie wrote:
...
>
> I diabled the hardware compression before I used the tapes for
the first time like it's described in the docs. mt shows me that
hardware compression is off after inserting a tape. So I think that
it's really disabled.
>
The switch may not occur unless the drive actually attempts to read the tape.
Amanda does an initial read before any attempt to write to a tape to
check if it
is actually an amanda tape and is the expected amanda tape.
I'll take a look at this later.
> > Amanda also tracks the amount of compression on a per dle
basis, so if you
> > know beforehand the ratio, you can put it in the dumptype spec
section to
> > give amanda a head start on a good guess.
>
> How can I put the ratio in the dumptype spec?
Can't. The history of last 3 dumps at full and incremental levels is recorded
in the curinfo file for the DLE after a dump. I wonder (don't know)
if you could
clear or edit that file or the relevant lines.
$ grep comp <curinfo_dir>/<host>/_<DLE>/info
full-comp: 0.386351 0.386012 0.385504
incr-comp: 0.196589 0.207102 0.197036
$
The DLE I ran this sample on shrink to about 38% and 20% of the original size
for full and incremental dumps respectively.
My curinfo files look like this:
:full-comp: 1.403959 1.404711 1.404836
:incr-comp: 1.953383 1.707214 1.944336
:full-comp: 0.998471 0.998600 0.999358
:incr-comp: 0.658643 0.633644 0.635077
info:full-comp: 1.470862 1.470858 1.470862
info:incr-comp: 1.920387 1.905384 1.905772
info:full-comp: 1.048603 1.048608 1.048625
info:incr-comp: 0.225497 0.260856 0.228623
info:full-comp: 1.587112 1.587132 1.587116
info:incr-comp: 0.025000 0.691057 0.681301
info:full-comp: 1.264800 1.264797 1.264808
info:incr-comp:
I have a problem with interpreting these values because they're
bigger than 1. For example in the first lines. Does this mean that my
backup shrinked by 140 %? Or does it grow by the factor of 1.4?
Thanks a lot to everybody helping me!
Sebastian