> A quick question. When I take backup of client using
> ADSM, and the compression of data is done at the
> client level, which implies that our 3575 getting the
> data is already compressed?.  The question is how the
> 3575 compresses the data. For example the 3575-L32 can
> stored 1.6GB native and 4.8TB compressed. How can I
> get the 4.8TB compressed with ADSM? is it the SW or
> the 3575 that does the compression?

Jason,

     If the clients do the compression, then you will only see "native"
capacities on the tapes (5GB/tape), and in the Library as a whole.  In
addition, keep in mind that compressing already compressed files can cause
the files to actually grow.  However, if a client compresses a 1GB file
down to 400MB, the 3570 will show about 400MB on tape, but that represents
1GB of client data.

Confused?  I hope not.  I force client side compression OFF, and allow the
3570's hardware compression to do it's stuff.  The downside of this is
more data over the network, and in the disk storage pool.  The up side is
that the speed of the backup is not limited by the CPU power on the client
to do the compression, and you get a truer measure of how much data is on
your tapes, and in your library.

Steve (unVMix Systems Programmer/Dude) Roder
(tkssteve AT ubvm.cc.buffalo DOT edu | tkssteve AT acsu.buffalo DOT edu | 
(716)645-3564 ,
   | http://ubvm.cc.buffalo.edu/~tkssteve)