A stgpool can get its tape volumes two ways.

You can define a whole set of tapes exclusively to a tape pool
and then adsm will manage those tapes for that specific tapepool.
For each tapepool and also for your DB backups you had to carve up
all your tapes into smaller pools each group for each stg pool

Or you can define tapes to the scratch pool and then adsm manages
them for all requests for scratch tapes.

I did this both ways when I ran Ver 2 on VM.
At the time I had a tape manager that could not manage scratch
allocation but could only manage requests for specific volumes
so I would define B0001,B0002,B0003 to BackPoolX.  When BackPoolX
filled B0001 all the way ADSM would ask for B0002 and start using it, etc.
THis would cause me to have to allocate 6 tapes to BackPoolX
and 5 other tapes to BackPoolY and DB backups had to ask for
tapes from its own pre-reserved set of tapes.

We then switched to a Tape Manager that managed scratches
So I could allocate 15 tapes to scratch and they would get assigned
to whatever stgpool or DB backup that asked for them first.
So all 15 tapes could be assigned to any process that needed a tape.

With non-VM and/or Ver 3 servers this tape management was integrated
into ADSM for Robot/Library support.  But you can still reserve tapes
for a specific stgpool.  Just keep in mind that if maxscr>0 then
ADSM will as for SCRATCH when it runs out of pre-defined/reserved tape
volumes!!!!

Hope this helps ..... :-)  ... joe.f.

Joseph A Faracchio,  Systems Programmer, UC Berkeley


On Thu, 20 Apr 2000, Jim Coen wrote:

>     I have two questions, SO elementary as to be embarrassing:
>
>     1. What is the difference between 'defining a volume' and
>        'checking in a volume'?
>
>     2. I have a 20-cart Magstar tape library. It simply will not
>        use two of the tapes--they remain completely empty even
>        though ADSM tries to migrate and fails.
>
>     Thanks for the good advice.
>
>     Jim
>
>     Jim Coen
>     Washburn University
>