Administrator's Guide

Figure 4 Relationship of primary versus secondary volume groups on primary and backup storage
servers
Remote Copy pairs
Remote Copy configurations are based on the relationship between a storage system pair, also
known as the Remote Copy pair. Within this pair, the primary storage system is the system that
holds the volumes that are copied to a backup or secondary storage system, also known as a
remote storage system.
Remote Copy volume groups
Remote Copy operations are performed on groups of virtual volumes called Remote Copy volume
groups. A Remote Copy volume group is a group of volumes on the same storage system that are
logically related and for which there is a cross-volume ordering of writes. Remote Copy volume
groups are used when data needs to be consistent across a group of volumes in order for databases
or other applications to process data correctly.
Remote Copy uses volume groups to define a set of volumes for which applications might issue
dependent writes.
Remote Copy ensures that the data in the volumes within a group maintain write consistency. When
Remote Copy operations are started or stopped, this is done for the whole group. When point-in-time
snapshots of such volumes are created, writes to all volumes in the group are blocked for a brief
moment to assure a consistent point-in-time copy of the whole Remote Copy volume group.
You must configure a single Remote Copy volume group for a cluster group in Windows clustering.
This Remote Copy volume group must include all virtual volumes being used for the application
service. The Remote Copy volume group is the unit in which HP 3PAR Cluster Extension failover
operations are carried out. A given HP 3PAR Cluster Extension cluster resource can manage only
one Remote Copy volume group.
Processes and components 11