Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

7-12 TrueCopy for z/OS Usage Scenarios
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
Transferring Operations Back to the Main Site
Once the applications are running at the remote site, the next activity is to
restore the main site and transfer operations back to the main site. To transfer
operations to the main site:
1. Bring up the host system at the main (primary) site, and ensure that all TCz
components are fully operational.
2. At the main site, release all TCz pairs at the MCUs. Use the Deleting Mode-
All option to release all TCz sync pairs in each CU. Use the Delete Range-
Group option to release all TCzA pairs in each group. Make sure to connect
with all MCUs and all CUs to release all TCz pairs.
3. At the main site, delete all TCzA consistency groups at the MCUs.
4. At the main site, delete the RCUs. Remember to connect with each MCU and
each CU to make sure that all RCUs have been deleted.
5. At the main site, configure the MCU ports as needed. If you plan to use the
same remote copy connections to copy back, change the existing initiator
ports to RCU target ports. If system option mode 114 is enabled on all MCUs
and RCUs, the ports will reconfigure automatically if you use the CESTPATH
command to add the pairs at the secondary site. Note: For fibre-channel
interface, do not use the CESTPATH and CDELPATH commands at the same
time as the SCSI path definition function of LUN Manager. The fibre-channel
interface ports need to be configured as initiator ports or RCU target ports
before the CESTPATH and CDELPATH commands are issued.
6. If you plan to use the same channel extenders, change the operating mode to
the opposite 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 remote site, configure the RCU ports to enable TCz operations in the
reverse direction (change RCU target ports to initiator ports for fibre). This
enables the original RCUs to send TCz remote copy operations to the original
MCUs to bring the original M-VOLs up to date. If system option mode 114 is
enabled on all MCUs and RCUs, the ports will reconfigure automatically if you
use the TSO CESTPATH command to add the pairs at the remote site. Note:
For fibre-channel interface, do not use the CESTPATH and CDELPATH
commands at the same time as the SCSI path definition function of LUN
Manager. The fibre-channel interface ports need to be configured as initiator
ports or RCU target ports before the CESTPATH and CDELPATH commands
are issued.
Caution: Before issuing the CESTPATH command, you must make sure
that the relevant paths are offline from the host(s) (e.g., configure the
Chipid offline, or deactivate the LPAR, or block the port in the ESCD). If
any active logical paths still exist, the add path operation will fail because
the port mode cannot be changed.