Software User Manual

to send XP Continuous Access remote copy operations to the original MCUs to bring the
original P-VOLs up to date.
8. At the remote site, establish the same XP Continuous Access Asynchronous groups and XP
Continuous Access pairs in the reverse direction to synchronize the original P-VOLs with the
S-VOLs. Make sure to use the Entire Volume initial copy option.
Resuming Normal Operations at the Primary Site
Once the XP Continuous Access pairs have been established in the reverse direction, you are ready
to resume normal operations at the primary (main) site. Remember that the XP Continuous Access
terminology is now reversed: the original RCUs and S-VOLs (secondary site) are now the MCUs
and P-VOLs, and the original MCUs and P-VOLs (primary site) are now the RCUs and S-VOLs.
To resume normal operations at the primary site:
1. At the secondary site, make sure that all XP Continuous Access pairs are in the PAIR (duplex)
state. This indicates that the XP Continuous Access initial copy operations are complete.
2. Halt the applications at the remote site, and vary the P-VOLs (original S-VOLs) offline at the
remote site. This maintains synchronization of the XP Continuous Access Synchronous pairs.
3. Split (pairsplit-r) all XP Continuous Access pairs at the MCUs (original RCUs) to destage any
pending data from cache. Confirm that the pairs are split (PSUS) before proceeding. If an
error occurs, resolve it before proceeding.
4. Release all XP Continuous Access pairs at the MCUs (original RCUs). You do not need to use
the Delete Pair by Force option. For XP Continuous Access Asynchronous pairs, the MCU and
RCU complete all pending updates before changing the pair status to SMPL.
5. Change the XP Continuous Access settings at the MCUs (original RCUs) to prepare for normal
XP Continuous Access operations. Delete the XP Continuous Access Asynchronous groups and
the RCUs (original MCUs). If you plan to use the same remote copy connections, reconfigure
the ports (change initiator ports back to ordinary target ports).
6. If you plan to use the same switches, change the operating mode back to the original direction
(see “Remote Copy Connections” (page 53)).
If you plan to use the same channel extenders, change the operating mode back to the original
direction. The boxes/nodes connected to the MCUs must be set to channel-mode, and the
boxes/nodes connected to the RCUs must be set to device-mode.
7. At the primary site, configure the initiator ports, add the RCUs, and add the XP Continuous
Access Asynchronous groups.
8. At the primary site, establish all XP Continuous Access groups and pairs in the original direction.
You may use the None initial copy option because all P-VOLs and S-VOLs are synchronized.
If there is any possibility that the volumes are not 100% synchronized, use the Entire Volume
initial copy option to be safe.
9. Vary the MCU and P-VOLs online, and start the applications at the primary site.
Using XP Continuous Access for Disaster Recovery Operations 151