We are currently running a 5.1.7.2 server under OS/390 and are looking
into the possibility of migrating to a mainframe Linux server. The Linux
server would share our existing 3494 tape library with the surviving
OS/390 workload. As TSM workload shifted from OS/390 to Linux we would
need to shift 3590 scratch tapes from OS/390 to Linux. We have so far
of two possible approaches, each with some ugly features. We are
wondering how other sites have handled this type of migration.

We use the CA-1 Tape Management System. Both approaches mentioned above
depend on modifying our cartridge entry exit to prevent it from laying
claim to volumes marked as deleted in the CA-1 database. Both approaches
call for updating the CA-1 database to mark departing scratch tapes as
deleted.

The two approaches diverge when it comes to getting the departing
scratch tapes out of the OAM database. One approach would simply
eject the tapes. When the tapes were reinserted OS/390 would not
claim them, and subsequent 'checkin libvol' commands on Linux would
claim them. This approach involves a lot of labor, some risk of
damage to tapes (especially the 3590 K tapes), and some risk
of confusion between tapes intended to go to our offsite vault and
tapes intended to go back into the 3494.

The second approach would use IDCAMS 'DELETE VOLUMEENTRY' commands
to remove the OAM database entries. Subsequent 'checkin libvol'
commands would claim the tapes for the Linux server. This approach
involves an end run around the normal mechanisms for managing a
database. We generally get very nervous about that sort of thing.