Problem with single-drive reclamation

Hi all,

We have an ADSM v3.1.1 srever running on AIX4.2.1, with an IBM 7337 DLT
(7000) library with one drive.  The server is running fine, apart from a
problem that has just started with the single-drive reclamation.
Unfortunately, I have been on vacation, and so am not 100% that something
has not been changed.  The storage pool setup is as follows:

Storage      Device       Estimated    Pct    Pct  High  Low  Next
Pool Name    Class Name    Capacity   Util   Migr   Mig  Mig  Storage
                               (MB)                 Pct  Pct  Pool
-----------  ----------  ----------  -----  -----  ----  ---  -----------
ARCHIVEPOOL  DISK             100.0    0.0    0.0    50    0  ARCHTAPEPO-
ARCHIVEPOOL  DISK             100.0    0.0    0.0    50    0  ARCHTAPEPO-
                                                               OL
ARCHTAPEPO-  DLTCLASS     716,800.0    0.3    5.0     0    0
 OL
BACKUPPOOL   DISK             300.0    0.0    0.0    60   40  TAPEPOOL
OFFSITEPOOL  DLTCLASS     716,800.0    7.9   25.0     0    0
RECLAIMPOOL  FILECLASS          0.0    0.0    0.0    60   40  TAPEPOOL
SPACEMGPOOL  DISK               8.0    0.0    0.0     0    0
TAPEPOOL     DLTCLASS     941,816.9   12.4   20.0     0    0

With the principal DLT pool being tapepool, and it is this that I am trying
to reclaim.  At present the reclamation is disabled (by setting the
reclamation threshold for tapepool to 99.  When I drop it to 50% the
following errors occur:

ANR2202I Storage pool TAPEPOOL updated.
ANR9999D afmigr.c(2544): Reconstruction of aggregates is disabled. Run
audit
reclaim utilities to re-enable reconstruction of aggregates.
ANR0984I Process 106 for SPACE RECLAMATION started in the BACKGROUND at
10:07:24.
ANR1040I Space reclamation started for volume C0002, storage pool TAPEPOOL
(process number 106).
ANR1044I Removable volume C0002 is required for space reclamation.
ANR8324I DLT volume C0002 is expected to be mounted (R/O).
ANR0985I Process 106 for SPACE RECLAMATION running in the BACKGROUND
completed
with completion state FAILURE at 10:07:24.
ANR9999D afmigr.c(2757): Space reclamation terminated for volume C0002 -
unexpected result code (3).
ANR1092W Space reclamation terminated for volume C0002 - internal server
error
detected.
ANR1042I Space reclamation for storage pool TAPEPOOL will be retried in 60
seconds.

An AUDIT RECLAIM command just completes immediately with no change, and
volume C0002 is in the library and appears to be just fine.

Does anybody have any ideas what might have happened?

Cheers,

Stuart

PS.  Could you copy me in when you reply (stuart AT dyadic DOT com)... Thanx