When you specify UNASSIGN with the MIGRATION parameter, UNASSIGN
specifies that the DASD migration level 2 volume is no longer associated
with its key range and is available for selection. If the volume
is a tape migration level 2 volume, DFSMShsm marks the volume as not
selected. Therefore, the tape migration level 2 volume is available
unless it is full.
Defaults: If you do not specify PURGE, REASSIGN,
or UNASSIGN, the default is UNASSIGN.
Note: - You can delete valid data from a tape backup volume or dump volume
if you specify the PURGE parameter. DFSMShsm deletes all control
data set information associated with each valid backup version dump
copy on the purged tape backup volume or dump volume. As a result,
DFSMShsm can no longer recover backup versions from the tape volume.
- You specify only a migration level 2 volume when you use the PURGE
or UNASSIGN subparameter with the MIGRATION parameter. If you specify
a migration level 1 volume, DFSMShsm ignores the parameter and a purge
is performed.
- If you use the PURGE parameter to remove a tape volume from control
of DFSMShsm and the tape volume is protected by a password or expiration
date, reinitialize the tape volume. You reinitialize the tape volume
with the IEHINITT utility. If you do not reinitialize the purged
tape volume and another program tries to write on the tape volume,
message IEC512I is issued and the tape volume is unloaded.
- If you do not reinitialize the purged tape volume, and if DFSMShsm
protected the tape volume with an expiration date, and another program
tried to write on the tape volume, the following occurs:
- Message IEC507D is issued.
- The operator is prompted to approve or disapprove the attempt
to write over an expiration-date-protected data set whose expiration
date has not been reached. If the operator disapproves the use of
the tape volume, the tape volume is unloaded and removed from the
inventory of backup or migration volumes.
- Messages IEC512I and IEC507D occur only if the program trying
to write on the tape volume is not using the volume verification exit
to override the password or expiration date protection on the first
file on the tape volume.
- If you use the ADDVOL command to add a purged tape volume to the
list of tape volumes owned by DFSMShsm and the purged tape volume
was previously protected by a password or expiration date, reinitialize
the tape volume. If you do not reinitialize the purged tape volume
and another program tries to write on the tape volume, message IEC512I
is issued, the tape volume is unloaded, and the tape volume is removed
from the inventory of backup, dump, and migration volumes.
- If a dump volume has more than one dump copy stacked on it, you
must use the PURGE parameter to delete the volume.