Hitachi MP-96RD625-01 Computer Drive User Manual


 
2-38 Chapter 3 Preparing for Universal Replicator z/OS Operations
Hitachi Universal Replicator for IBM /OS User’s Guide
Group This URz volume pair was suspended along with the other pair in its journal group. Update
sequence consistency between this secondary data volume and other secondary data
volumes in this journal group is ensured. This secondary data volume can be used for disaster
recovery at the secondary system (after releasing the URz volume pair from the secondary
storage system). This status is indicated when:
This volume pair was suspended by a user-initiated suspend pair operation with the
URz Suspend option set to Group.
All volume pairs in this journal group were suspended due to a failure that affected
the entire journal group (not just one pair) (e.g., primary storage system-secondary
storage system communication failure).
The volume pair was suspended due to a failure that did not affect the entire group.
Suspension Condition
URz operations also involve suspension conditions related to asynchronous
operations. Both the primary storage system and secondary storage system
can detect URz suspension conditions and suspend URz pairs.
The URz suspension conditions described in
Table 2-7 and indicates which CU
detects the condition and which pairs are suspended. See section
General
Troubleshooting for troubleshooting information for URz suspension conditions.
Table 2-7 URz Suspension Condition
Suspension Condition Detected by: URz Pairs to be Suspended
The secondary storage system could not copy the
journal data successfully due to a hardware failure or
logic error.
RCU
All URz secondary data volumes in the
journal groups, or the affected
secondary data volume.
The secondary storage system detected a logical error
while selecting the journal data to be restored.
RCU
The secondary storage system could not restore the
journal data due to a hardware failure, track condition,
or logical error.
RCU
All the URz secondary data volumes in
the journal group, or only the affected
secondary data volume, depending on
the type of failure.
The primary storage system stores the differential bitmap per URz primary
data volume in the shared memory. The secondary storage system stores the
differential bitmap per URz secondary data volume in the shared memory.
When a URz pair is suspended, the tracks which contain the following journal
are marked in the differential bitmap as modified (to be copied during the
resume pair operation):
The journal data that were created by the primary storage system but not
yet sent to the secondary storage system.
After marking these primary data volume tracks as modified, the primary
storage system discards these journal data.
The journal data that were sent to the secondary storage system but not
acknowledged by the secondary storage system.