HP 3PAR Operating System Software - Manual (Page 101)

System Roles and Direction of Data Flow
Under normal operating conditions, the natural direction of data flow is from the primary volume
group to the secondary volume group.
HP 3PAR remote copy replicates data from primary volume groups, which you name, and which
are kept on the primary system, to secondary volume groups, which HP 3PAR Remote Copy names,
and which are kept on the backup system.
For additional information, see the following:
•
“Creating Volume Groups for Unidirectional Remote Copy” (page 82)
•
“Working with Volume Groups” (page 110)
•
“Natural Direction of Replication” (page 113)
Changing the Direction of Data Flow
Under the following circumstances, you must temporarily switch the direction of data flow:
•
Disaster recovery
•
System maintenance/replacement
•
Scheduled downtime
Switching the direction of data flow temporarily reverses the replication direction of the volume
groups.
For additional information, see the following:
•
“Recovering from Disaster” (page 162)
•
“Changing Secondary Volume Groups to Primary” (page 117)
System Roles and Bidirectional Configurations
In bidirectional configurations, both systems in the remote-copy pair serve as both primary and
backup systems. The system role changes, depending on the volume group you are working with.
To distinguish the roles:
•
A primary volume group resides on the primary system.
•
A secondary volume group resides on the backup system.
See the following: For more information about:
“Sending Links” (page 102) Rules for creating and sending links
“Receiving Links” (page 104) How remote copy uses receiving links
Remote-Copy Target System 101