HP StorageWorks XP24000 Continuous Access Journal Software User and Reference Guide, v01 (T5278-96001, June 2007)

If power is removed from the p rimary or secondar y storage system and its backup batteries are fully
discharged while data volume pairs are split, differential data (that is, update data) will not be retained.
In this unlikely case, the primary or secondar y storage system assumes all the s uspended data volumes
are updated. If you restore the data volume pairs at the primary site, all the primary data volumes
will be copied to the secondary data volumes.
When the Power is Removed from Network Relay Devices
If power is removed from a network relay device during remote copy operations, the primary and
secondary storage systems assume that a failure o ccurred, and then split all data volume pairs.
Turning the Power O ff Intentionally
This section explains what should be noted when you power off storage systems or network relay devices
intentionally.
When You Power Off the Primary Storage System
To power off the primary storage system during remote copy operations, you must ensure, before
powering off the storage system, that all data volume pairs or mirrors (that is, pairs of journal groups) are
split, and that the status of all the data volume pairs is PSUS.
Caution: To power off the primary storage
system, ask your HP service representative to p ower off the storage system.
If data volume pairs a re split and the primary storage system is powered off as mentioned above, you
can
resume remote copy operations by taking the following steps:
1. Power on the primary storage system.
2. If the primary storage system is ready to resume remote copy operations, restore the data volume
pairs that have been split, and then confirm that the status of the data volume pairs is COPY or
PAIR.Th
is
operation must be performed at the primary site.
After you take these steps, remote copy operations will be resumed. The primary storage system will be
able to respond to read journal commands issued by the secondary storage system.
Note: To power off both the primary and secondary storage systems at the sam e time, see
“When You Power Off the Primary and Secondar y Storage Systems at the Same Time”onpage108.
Note: If you turn the power off without changing the status of all data volume pairs to PSUS, and then you
turn the power back on, the status of all data volume pairs could be suspended due to a failure.
When You Power Off the Secondary Storage System
To p ower off the secondary storage system during remote copy operations, you must ensure, before
powering off the storage system, that a ll data volume pairs or mirrors (that is, pairs of journal groups)
are split, and that the status of a ll the data volume pairs is PSUS.
Caution: To power off the secondary
storage system, ask your HP service representative to power off the storage system.
If data volume pairs are split and the secondary storage system is powered off as mentioned above, you
can
resume remote copy operations by taking the following steps:
1. Power on the secondary storage system.
2. If the seconda ry storage system is ready to resume remote copy operations, restore the data
volume pairs that have b een split, and then confirm that the status of the data volume pairs is
COPY or PAIR. This operation must be per formed at the primary site.
After you take these steps, remote copy operations will be resumed. The secondary storage system will be
able to issue read journal commands to the primar y storage system.
Note: To power off both the primary and secondary storage systems at the sam e time, see
“When You Power Off the Primary and Secondar y Storage Systems at the Same Time”onpage108.
Note: If you turn the power off without changing the status of all data volume pairs to PSUS, and then you
turn the power back on, the status of all d ata volume pairs could be s uspended acc ording to a failure.
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