Joey,

I faced a similar dilemma when I was starting to develop an ADSM strategy
and found that, yes, you can have different types of pools.  The trick is
in defining seperate copy groups.  Here's the scenario that I have
used.  I defined a DASD based pool named BACKUPPOOL.  When it hits the
threshold, it will migrate to a tape based pool named TAPEPOOL.  I also
defined a seperate pool named LANSERVERS which is also tape based.  I
then created seperate copy groups for each.   The STANDARD copy group
goes to BACKUPPOOL.  The LANSERVERS copy group goes directly to the
LANSERVERS tape based pool.  The trick, however is getting the files to
the correct copy group.  Since the STANDARD group goes to DASD, I allow
all of our regular, non-special PC's to default to that.  However, for
our LAN servers, we didn't want them to take up the DASD space since their
files won't change very often and take up a great deal of space.  Therefore,
in their DSM.OPT file, I specified an INCLUDE statement similar to the
following:

INCLUDE C:* LANSERVERS

This will bind all of the files on the C drive to the LANSERVERS copy group.

As it turns out, I actually wanted to run both styles of backups on the
same LAN server (ie. a server with user written files on it).  I wanted
to direct the user files to DASD and the rest of the server files to
tape.  I have managed to do this by having two different options files
on the server, one that binds to the STANDARD group and one that binds
to LANSERVER.  I have written REXX execs that will select the correct
options file for the type of backup being done and sets the DSM_CONFIG
variable accordingly.  It then invokes the DSMC program to either do
an incremental backup on the user subdirectories or a selective dump
of the entire server.  Currently, I'm the process of writing a TCP/IP
socket that will allow an operator on our VM system to fire up the tape
based backup whenever they wish.  This was necessary because the scheduler
in ADSM has several serious problems and didn't really meet our needs anyway.

I'm sure that there many other ways to approach this strategy, this was
just what seemed the most practical for us.  I'd be interested in hearing
how other places have approached it.

Martha