Joe,

This is an excerpt from the ADSM for AIX Admin Guide.  This will help
you get close, but as with so many things concerning ADSM the real
answer is "it depends,"  your results may vary


"Estimating database or recovery log space requirements"
The size of your ADSM database depends on the number of client files to
be stored and how ADSM manages them. If you can estimate the maximum
number of files that might be in server storage at any time, you can use
the following information to come up with a useful database size
estimate:

Each version of a file that ADSM stores requires about 400 to 600
bytes of database space.
Each cached or copy storage pool copy of a file requires about 100 to
200 bytes of database space.
Overhead could increase the required space up to an additional 25%.

--
Ray Pratts
Ray Pratts
Pinnacle Computer Solutions, Houston, Tx
Tel. 281-272-8932    E-mail: pratts AT ibm DOT net


Joe Jedynak wrote:
>
> At the moment we are just using ADSM for back-ups. Now we are planning to add 
> HSM and Disaster Rec product. We have 20gig on our WS. Has anyone found a 
> good rule of Thumb in calculating required disk space For Adsm Database and 
> spool space. Thanks Joe J.