Back when we had a 3494 with two types of tapes, we controlled who wrote to 
what by making two separate devclasses.  One type of tape was all explicitly 
defined volumes to one of the devclasses, the other type of tape were used as 
scratch tapes in the other devclass.

David

>>> "Sheppard, Sam" <SSheppard AT SDDPC DOT ORG> 5/19/2010 5:41 PM >>>
We are running TSM 6.1.3.4 on AIX with a 3494 library and 8 TS1120 (E05) tape 
drives. I keep thinking there should be a way to do this, but I'm coming up 
dry.  We are about to implement NDMP for several large filesystems.  I was 
thinking it would be nice (and cheaper) to use the higher capacity JB tapes 
specifically for NDMP, since there will be a lot of large full backups.  We 
chose to originally go with JA tapes on the theory that we would end up with 
less wasted space.  My problem is I can't think of a way to segregate the 
larger tapes from the smaller ones to enable their use only for NDMP.  The only 
thing I can think of so far is a new DEVCLASS that only specifies 
3592-2,3592-2c and point the storage pool at that device class, but that still 
doesn't give me any way of getting the data to only the 3592JB tapes.

Anyone have any ideas, or should I just bite the bullet and just let them mix.

Thanks
Sam Sheppard
San Diego Data Processing Corp.
(858)-581-9668