HP XP Continuous Access Software - Manual (Page 102)

102 Continuous Access XP for the XP1024/XP128
Transferring operations back to primary sites
After applications are running at the secondary (remote) site, the next activity is to restore the primary
(main) site and transfer operations back to the primary site.
1. Bring up the host servers at the primary site, and ensure that all Continuous Access XP components are
fully operational.
2. At the primary site, delete all Continuous Access XP pairs at MCUs. The Delete Pair by Force option
must be Yes because previous S-VOLs are in the SMPL state at the secondary site.
3. At the main site, delete all Continuous Access XP Async consistency groups at MCUs.
4. At the main site, delete RCUs. Remember to connect with each MCU and each CU image to ensure
that all RCUs are deleted.
5. At the main site, configure MCU ports as needed. If you plan to use the same remote copy connections
to copy back, change existing RCPs to LCPs, or change existing initiator ports to ordinary target ports.
6. If you plan to use the same channel extenders, change the operating mode to the opposite direction.
Boxes and nodes connected to MCUs must be set to channel-mode. Boxes and nodes connected to
RCUs must be set to device-mode.
7. At the remote site, configure appropriate ports to enable Continuous Access XP operations in the
reverse direction (change target ports to initiator ports for fibre, change LCPs to RCPs for serial). This
enables the original RCUs to send Continuous Access XP remote copy operations to the original MCUs
to bring the original P-VOLs up to date.
8. At the remote site, establish the same Continuous Access XP Async groups and Continuous Access XP
pairs in the reverse direction to synchronize the original P-VOLs with the S-VOLs. From the Paircreate
parameter pane, select Entire Volume for the Initial Copy field for the Initial copy parameters option.
Resuming normal operations at primary sites
After Continuous Access XP pairs are established in the reverse direction, you are ready to resume normal
operations at the primary (main) site. Remember that the Continuous Access XP terminology is now
reversed: original RCUs and S-VOLs (secondary site) are now MCUs and P-VOLs, and original MCUs and
P-VOLs (primary site) are now RCUs and S-VOLs.
1. At the secondary site, ensure that all Continuous Access XP pairs are in the PAIR (duplex) state. This
indicates that Continuous Access XP initial copy operations are complete.
2. Halt applications at the remote site, and vary P-VOLs (original S-VOLs) offline at the remote site. This
maintains synchronization of Continuous Access XP Sync pairs.
PSUE-Group Yes Update sequence consistency across these S-VOLs is ensured at the point in time
indicated by the consistency time. These S-VOLs can be used for disaster
recovery at the secondary system.
Updates performed at the primary system after the indicated consistency time
were probably lost.
PSUE-LU No Contents of this S-VOL might be behind other S-VOLs in the consistency group. If
this volume must be consistent with other volumes in the same group, this S-VOL
should not be used for disaster recovery.
The cause for this status is:
• The Continuous Access XP Async Error Level pair option for this pair is LU
(not Group).
• This pair was suspended before disaster or failure, at the beginning of the
rolling disaster, or during the initial copy operation.
Table 21 Determining Continuous Access XP Async S-VOL consistency based on its pair status and
consistency status (continued)
Status of
S-VOL
Usable for
Recovery?
Description