HP XP Continuous Access Software User Manual
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secondary data volume in shared memory. When an XP Continuous Access Journal pair is
suspended, tracks containing the following journal are marked in the differential bitmap as modified
(to be copied during the pairresync operation):
•
Journal data the primary array has created, but has not sent to the secondary array yet
After marking these primary data volume tracks as modified, the primary array discards the
journal data.
•
Journal data that has been sent to the secondary array, but has not been acknowledged by
the secondary array
After marking these primary data volume tracks as modified, the primary array discards the
journal data. This ensures that journal data lost during transmission to the secondary array is
identified and marked.
•
Journal data that has reached the secondary array, but has not been restored yet
After marking these primary data volume tracks as modified, the primary array discards the
journal data. Therefore, the secondary array can check and mark journal data that has not
been restored.
The primary array does not discard journal data from the master journal volume until the
primary array receives the restored journal volumes' sequence numbers, which are included
in read journal commands from the secondary array.
•
Primary data volume records updated by host-requested write I/Os after the pair was suspended
describes XP Continuous Access Journal suspension conditions and indicates
which CU detects the condition and which pairs are suspended. See
for troubleshooting information for XP Continuous Access Journal suspension
conditions.
Table 7 XP Continuous Access Journal suspension conditions
XP Continuous Access Journal pairs to
be suspended
Detected by
Suspension condition
All XP Continuous Access Journal
secondary data volumes in the journal
groups, or the affected secondary data
volume
RCU
The secondary array could not copy
the journal data successfully due to a
hardware failure or logic error.
All XP Continuous Access Journal
secondary data volumes in the journal
group, or only the affected secondary
volume
RCU
The secondary array detected a
logical error while selecting the journal
data to be restored.
All XP Continuous Access Journal
secondary data volumes in the journal
groups, or the affected secondary data
volume
RCU
The secondary array could not restore
the journal data due to a hardware
failure, track condition, or logical
error.
XP Continuous Access Journal data volume pair status
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