Urz suspension condition, Business continuity manager support, Suspension condition – HP StorageWorks XP Remote Web Console Software User Manual
Page 35: Suspension, Condition
URz 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.
describes the URz suspension conditions and indicates which CU detects the
condition and which pairs are suspended. See
for troubleshooting
information for URz suspension conditions.
Table 7 URz Suspension Condition
URz Pairs to be Suspended
Detected by:
Suspension Condition
All URz secondary data volumes in
the journal groups, or the affected
secondary data volume.
RCU
The secondary storage system could not copy the
journal data successfully due to a hardware failure or
logic error.
All the URz secondary data volumes
in the journal group, or only the
affected secondary data volume,
depending on the type of failure.
RCU
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.
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 data 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.
After marking these primary data volume tracks as modified, the primary storage system
discards these journal data. This ensures that journal data lost during transmission to the
secondary storage system are identified and marked.
•
The journal data that reached the secondary storage system but have not yet been settled.
After marking these secondary data volume tracks as modified, the secondary storage system
discards these journal data.
•
The primary data volume records updated by host-requested write I/Os after the pair was
suspended.
When a suspended URz pair is resumed (resynchronized), the contents of the secondary storage
system’s cylinder/track bitmap are sent to the primary storage system and merged into the primary
storage system’s bitmap. The primary storage system then performs the resync operation according
to the merged bitmap. This ensures that all the tracks including the discarded journal data are
resynchronized at this time.
Business Continuity Manager Support
The XP storage systems on which URz is installed support the Business Continuity Manager
commands. If the host system console issues the Business Continuity Manager commands to the XP
storage system, the URz pair operations can be performed. The Business Continuity Manager
commands allow you to add pairs, suspend pairs, resume pairs, release pairs, monitor the pair
Business Continuity Manager Support
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