z/OS® DFSMS V2 provides the following enhancements
to the object access method (OAM):
- OAM now supports tape block sizes larger than 32760. A new TAPESDB
keyword on the SETOAM statement in the CBROAMxx PARMLIB member can
be set to enable larger block sizes. When the first object is written
to an OAM tape volume, the maximum block size for the volume is established.
If support for larger tape block sizes is enabled, that maximum block
size is set to the optimal system-determined block size for the device.
Otherwise, a maximum block size of 32760 is used. The maximum block
size for all objects written to a tape volume is the maximum block
size for the volume established when the first object was written
regardless of the current SETOAM TAPESDB setting.
- OAM now provides a new ALLOCRETRYMINUTES keyword on the SETOAM
statement in the CBROAMxx PARMLIB member, which can be set to control
how long OAM makes retry attempts or to bypass retry processing entirely
and issue CBR6400D immediately. This can be used with ATAM (Automated
Tape Allocation Manager) processing.
- The minimum object size required to utilize Store Sequence processing
(STOREBEG, STOREPRT, STOREEND) has been reduced from the previous
limit of 256MB+1 to 50MB+1 for all objects except those being written
to an optical volume.
- Previously, when OSMC moved an object to a different management
class, existing backup copies of the object were kept. If the object
moves to a management class that requires fewer (or no) OAM backup
copies, the extra backup copies remained, but were no longer needed
and waste storage space. OAM now provides a new BACKUPDELETE keyword
on the SETOSMC statement in the CBROAMxx PARMLIB member which can
be set to indicate that OSMC should delete all unneeded OAM backup
copies when processing an object.
- OAM now provides a new SETTLIB statement for tape
library settings. The optional SETTLIB statement and its associated
keywords in the CBROAMxx PARMLIB member can be used to override the
default behavior for some of the main cartridge entry messages in
a system managed tape library environment. The SETTLIB statement
and keywords are processed when the OAM address space is started and
cannot be updated by operator command. The SETTLIB statement can be
used to specify:
- How OAM will display volume entry ignore messages during cartridge
entry processing (DETAIL, SUMMARY, or SUPPRESS).
- Where OAM will display volume entry ignore messages during cartridge
entry processing (on both the console and system log or only on the
system log).
- Where OAM will display successful volume entry messages (CBR3610I)
during cartridge entry processing (on both the console and system
log or only on the system log).