HP StorageWorks XP Remote Web Console Software - Manual (Page 153)

If power is removed from the primary or secondary 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 secondary storage system assumes all the suspended
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 occurred, and then split all data volume pairs.
Turning Off Power Intentionally
This section explains what should be noted when you power off storage systems or network relay
devices intentionally.
Powering 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 Suspend.
If more than one primary and secondary storage systems is used with extended consistency groups,
you must split all data volume pairs in the extended consistency groups before powering off the
primary storage systems. When powering off the primary storage systems, you must power off the
supervisor DKC first, and then the subordinate DKCs.
If the delta resync function to support the remote command devices is used, the SIM (SIM reference
code = EFD0) to suggest that the device connected to the external storage system has been blocked
is reported to the destination storage systems because the command devices are blocked due to
the power-off of the storage system.
CAUTION: To power off the primary storage system, contact your HP service representatives and
ask them to power off the storage system.
If data volume pairs are 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.
If more than one primary storage system is to be used with extended consistency groups,
power on the subordinate DKCs first, and then the supervisor DKC.
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
Pending duplex orDuplex. This 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 same time, see “Powering
Off the Primary and Secondary Storage Systems at the Same Time” (page 154) .
•
If you turn the power off without changing the status of all data volume pairs to Suspend, and
then you turn the power back on, the status of all data volume pairs could be suspended
according to a failure.
When You Power Off the Secondary Storage System
To power off the secondary 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 Suspend.
Managing Power for Storage Systems and Network Relay Devices 153