HP XP Racks - Manual (Page 166)

Alternative configuration to im-
plement requirement
Requirement for configuration Unsupported configuration
None None
Pairs in the copy group use the
same S-VOL.
There are different types of copy
pairs in the same copy group.
Unify the P-VOLs using the same
storage system into the same
CTG*.
To perform an operation simultan-
eously on pairs that span multiple
storage systems.
The storage systems for the primary
volumes in the same copy group
are different.
Unify the S-VOLs using the same
storage system into the same
CTG*. The storage systems for the second-
ary volumes in the same copy
group are different.
Divide the destination copy groups
into multiple CTGs according to the
cascade source CTGs.
To perform an operation simultan-
eously on pairs that span multiple
storage systems, without maintain-
ing consistency.
The cascade configuration consists
of a container and a copy group.
Create CTGs in the cascade source
according to the cascade destina-
tion copy groups. Pairs in the cas-
cade source must belong to any
CTG.
To create a backup of only some
volumes. The cascade destination contains
multiple copy groups.
Legend:
*: When primary volumes and secondary volumes in the same copy group belong to different storage
systems, it is necessary to create CTGs with volumes that have the same combination of primary and
secondary storage systems.
About delta resync
In a 3DC multi-target configuration, there is one primary site and two secondary sites. Continuous
Access Synchronous and Continuous Access Journal are used to copy storage system volumes among
the three sites (called a data center). Continuous Access Journal provides the primary site and
Continuous Access Synchronous and Continuous Access Journal provide the secondary sites. Replication
Manager can be used to configure a Delta Resync pair using the two secondary sites. Delta Resync
pairs are stand-by pairs for providing additional redundancy in 3DC multi-target configurations.
Continuous Access Journal provides the delta resync operation as a way to recover from failures in
the primary site. If a failure occurs at the primary site in a 3DC multi-target configuration, the P9000
RAID Manager
horctakeover command is used to reconfigure the Continuous Access Synchronous
secondary site as the primary site. If the delta re-synchronization function is used between the primary
and secondary sites, journal-copying of only the minimum data required is performed following a
failure, minimizing the recovery time.
Related topics
• Creating a 3DC multi-target configuration , page 167
• Limitations when performing 3DC configuration pair operations (mainframe systems) , page 167
Managing pair life cycle 166