HP XP Continuous Access Software - Manual (Page 36)

For information about the delta resync operation that is performed when a failure occurs in the
configuration shown in Figure 7 , see Switching Continuous Access XP's master journal group . The
contingency Continuous Access XP Journal pair must be in HOLD status when the failure occurs in order
to perform a delta resync operation. However, the contingency Continuous Access XP Journal pair status
can be changed to HLDE, for example, when a cache memory or shared memory error occurs at the
DC2 Continuous Access XP Synchronous secondary site or when you cannot obtain a journal at the
Continuous Access XP Synchronous secondary site because the master journal volume failed or a pinned
track occurred. If the status of the contingency Continuous Access XP Journal pair for a delta resync
operation changes to HLDE due to one of the conditions described above, follow the steps in Restoring a
pair of data volumes and change the pair status back to HOLD again.
Switching Continuous Access XP's master journal group
When a failure occurs on the DC1 primary site in Figure 7 (3DC multi-target configuration), the
DC2-to-DC3 Continuous Access XP Journal pair can then use the contingency journal group in the
Continuous Access XP Synchronous secondary site as the new master journal group. To switch the master
journal group, first change the Continuous Access XP Synchronous secondary site to a primary site using
RAID Manager XP's horctakeover command, and then perform a delta resync operation on the primary
data volume of the contingency Continuous Access XP Journal pair that was in HOLD status to activate
data flow for that logical connection. Figure 8 shows an example.
36 Overview of Continuous Access XP Journal