In order for a data set to be moved for a class transition, it
must be closed and unallocated so that DFSMSdss can serialize on the
data set and move it with full data integrity. Since class transitions
are desirable for many types of data sets that are always open, the
new management class
"Serialization Error Exit" setting specifies
which action DFSMSdss should take if it cannot initially serialize
a data set. Possible values for this setting are:
- NONE
- specifies that the transition should fail with no additional action.
This is the default. As a default, DFSMShsm does not issue error messages
for data sets that fail serialization. If you wish to ensure that
these types of error messages are issued, use PATCH .MGCB.+EF
BITS(...1....)
- DB2
- specifies that DB2 should be invoked to close the data set. If
there are no DB2 transactions in progress and the data set is successfully
closed and unallocated, then the data set will be exclusively serialized.
If exclusive access is obtained, then the data set will be transitioned.
After the data set has moved, DB2 is reinvoked to allocate and open
the data set. If the serialization cannot be obtained or there are
active DB2 transactions, then the transition will fail.
Only DB2
objects should be assigned to a management class with this setting.
- CICS
- specifies that CICS should be invoked to make
the data set unavailable for use by CICS and to close all files open
to the data set. If these steps are successful, then the data set
will be exclusively serialized and then transitioned. After the data
set has moved, CICS is reinvoked to enable the CICS files to use the
data set and make available the data set to be used by CICS. If the
serialization cannot be obtained a second time, then the transition
will fail.
Only CICS data sets should be assigned to a management
class with this setting.
- ZFS
- specifies that zFS should be invoked to unmount the data set.
If the data set is successfully unmounted, then the data set will
be exclusively serialized. The unmount will fail if the file system
is currently accessing the data set. If exclusive access is obtained,
then the data set will be transitioned. After the data set has moved,
zFS is reinvoked to mount the data set.
Only zFS data sets should
be assigned to a management class with this setting.
- EXIT
- specifies that a user exit should be invoked to unserialize the
data set. The exit will be invoked twice: initially to unserialize
the data set, and a second time after the transition in order to reserialize
the data set. The transition will be performed if the data set can
be exclusively serialized after the user exit has been initially invoked.
A valid exit should be in place before this option is specified. No
default exit is provided.