HP XP Continuous Access Software - Manual (Page 41)

Table 8 Suspend Types (PSUE) (continued)
Description Applies to Type
In this case, the secondary data volume suspend type is usually
PSUE-S-VOL Failure.
The primary storage system could not find valid control information
in its nonvolatile memory during an IMPL. This condition occurs only Primary data volume,
Secondary data volume PSUE, MCU
IMPL
if the primary storage system is without power for more than 48
hours (that is, a power failure and fully discharged backup batteries).
The XP Continuous Access Journal pair was suspended before the
initial copy operation was complete. The data on the secondary data
volume is not identical to the data on the primary data volume. Primary data volume,
Secondary data volume PSUE, Initial
Copy Failed
The primary storage system is powered off. Secondary data volume PSUE, MCU
P/S OFF
Suspension Condition
XP Continuous Access Journal operations involve additional suspension conditions related to the
asynchronous journal operations. Both the primary storage system and secondary storage system
can detect XP Continuous Access Journal suspension conditions and suspend XP Continuous Access
Journal pairs.
•
The primary storage system stores the differential bitmap for each XP Continuous Access Journal
primary data volume in the shared memory.
•
The secondary storage system stores the differential bitmap for each XP Continuous Access
Journal secondary data volume in the shared memory.
When an XP Continuous Access Journal pair is suspended, the tracks that contain the following
journals are marked in the differential bitmap as modified (to be copied during the pairresync
operation):
•
The journal data that was 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 this journal data.
•
The journal data that was 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 this journal data. This ensures that journal data lost during transmission to the
secondary storage system is identified and marked.
•
The journal data that reached the secondary storage system, but has not yet been restored.
After marking these primary data volume tracks as modified, the primary storage system
discards this journal data. Therefore, the secondary storage system can check and mark the
journal data that has not been restored.
The primary storage system does not discard journal data from the master journal volume until
the primary storage system receives the sequence numbers of the restored journal volumes.
The sequence numbers are included in the read journal commands from the secondary storage
system.
•
The primary data volume records updated by host-requested write I/Os after the pair was
suspended. The XP Continuous Access Journal suspension conditions described in
Table 9 (page
42) indicate which CU detects the condition and which pairs are suspended. See “General
Troubleshooting” (page 216) for troubleshooting information for XP Continuous Access Journal
suspension conditions.
Pair Status 41