HP StorageWorks XP Remote Web Console Software - Manual (Page 223)

secondary EXCTG, while the consistency of the data update sequence is maintained. On the other
hand, if a failure occurs in secondary storage system 1, journal groups 1 to 3 will be suspended
due to the failure, and the consistency of the data update sequence will not be maintained for the
secondary data volumes in the extended consistency group.
Figure 88 Example 2: Remote Copy Operations among Three Primary Storage Systems and Three
Secondary Storage Systems
Disaster Recovery Procedure
The following procedure is an example of the steps that should be taken when a disaster or failure
occurs in the primary site in a multi-primary and multi-secondary storage systems configuration:
1. Switch operations from the primary site to the secondary site.
2. Reverse the copy direction, so that data are copied from the secondary site to the primary
site.
3. After recovery of the primary host or storage system finishes, switch operations from the
secondary site to the primary site.
This disaster recovery procedure is the same as when only one primary storage system and only
one secondary storage system are used. For the detailed procedure, see
“Usage Monitor Window
Operations” (page 214) .
Disaster Recovery in a 3DC Cascading Configuration
If a disaster or failure occurs in the primary site in a 3DC cascading configuration, you can use
TrueCopy for Mainframe secondary volumes in the intermediate site to enable the intermediate
site to take over your business tasks. If a disaster or failure occurs in the primary site, first you must
transfer your business tasks from the primary site to the intermediate site.
To transfer your business tasks to the secondary site:
Performing Disaster Recovery Operations 223