HP StorageWorks XP Remote Web Console Software - Manual (Page 194)

5-24 Chapter 5 Configuring Storage Systems and Logical Paths
Hitachi Universal Replicator for IBM /OS User’s Guide
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 (i.e., 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
occurs, 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.
When You Power Off the Primary Storage System
If you want 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 (i.e., 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 are 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.
Caution : If you want to power off the primary storage system, please contact
your Hitachi account team 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,
please restore the data volume pairs that have been split, and then confirm
that the status of the data volume pairs is Pending duplex or Duplex.
This operation must be performed at the primary site.