Hi Tim,

I'll also be getting a 3570 to play with soon!!
The capacity you are seeing is correct if you do client compression. You see,
ADSM
will report the actual amount of data written to the tape. The drive uses the
same
algorithm as ADSM to achieve hardware compression on the drive's level. So, in
fact ADSM and the drive will get about the same compression ratio.
IBM claims a 3 to 1 compression ratio with the drives, so if you send 30Gigs of
uncompressed data to the drive you should fill the casette to it's physical
capacity(10 Gig). (This is mostly theory as some data compress more than
others).

So you have two options - if you have a good network and not very powerfull
client machines that you want backed up, disable the compression on the client
side and you will see ADSM reporting that it's writing between 20 and 40 Gig to

the casettes. But if you want to save on bandwidth and your machines can
handle the compression, do the compression at the client side and you will see
ADSM reporting as it's doing currently - approximately 10 Gig.

As you can see, there is NO difference in terms of how much data is stored on
the casette physically - it is just what ADSM will report that will look
different.
I know people like Dwight reported seeing some cassettes as reported by ADSM
using close to 70 Gig!

Hope this has helped.

Christo Heuer
Johannesburg
South Africa
Christoh AT absa.co DOT za




> I've just got my new Magstar 3570 B12 up and running.  I'm very pleased with
> how it is working.  However, I'm seeing about 10-11 GB per tape.  Is this
> my real limit or do is there something I can do to increase the cap.?
> Supposedly these drives can hold 10-30GB, I was kinda hoping for about 20 GB.
>
> Thanks.
> > Tim Dobrowolsky                   > <                yksloworboD miT <