This problem is very particular

I have occurances where a diskpool becomes full , or exceeds the Hi
threshold and a migration process starts.  Issuing a tape mount.
About 3 mins later in the activity log another tape is mounted for the same
tapepool.
 q proc  shows only 1 tape mounted for the migration process
q mount shows 2 tapes mounted and INUSE
 q vol f=d shows tapes are being updated
changing one of the tapes to read-only sets its status to IDLE ( in q mount
), produces an error  for a session from a node ???(Why as all backups go
directly to disk)
changing the tape back to readw , migration process continues to use the
tape.
I tried this again, this time mounted a new scratch tape , but still this
is not showing in q proc for the migration process


The storage pool has these settings

               Storage Pool Name: SP_DISK_POOL
               Storage Pool Type: Primary
               Device Class Name: DISK
         Estimated Capacity (MB): 4,000.0
                        Pct Util: 100.0
                        Pct Migr: 100.0
                     Pct Logical: 100.0
                    High Mig Pct: 90
                     Low Mig Pct: 85
                 Migration Delay: 0
              Migration Continue: Yes
             Migration Processes: 1
               Next Storage Pool: SP_TAPE_POOL
            Reclaim Storage Pool:
          Maximum Size Threshold: No Limit
                          Access: Read/Write
                     Description: SP Disk Pool for Filesystem Backups
               Overflow Location:
           Cache Migrated Files?: No
                      Collocate?:
           Reclamation Threshold:
 Maximum Scratch Volumes Allowed:
   Delay Period for Volume Reuse:
          Migration in Progress?: Yes
            Amount Migrated (MB): 437.13
Elapsed Migration Time (seconds): 453
        Reclamation in Progress?:
 Volume Being Migrated/Reclaimed:
  Last Update by (administrator): ADMIN
           Last Update Date/Time: 06-11-2000 13:13:38

Also dev mount retention set to 1 min


Now this is a problem as I'm using 3570 and only have 19 slots. The above
problem causes 2 tapes to be partially  filled wasting 1 valuble slot
TSM = 3.7.3.8
TSM client= 3.7.2.15

Is there somthing about the migration process that isn't documented or is
it a bug


 Regards Ped

( Pietro M D  Brenni )
IBM Global Services Australia
ZE06 (Zenith Centre - Tower A)
Level 6,
821 Pacific Highway
Chatswood NSW 2067
Sydney Australia
Ph:  +61-2-8448 4788
Fax: +61-2-8448 4006