HP StorageWorks XP Remote Web Console Software - Manual (Page 139)

TrueCopy for z/OS user guide 139
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 TC390 operations in the reverse direction (change
LCPs to RCPs for serial, change RCU target ports to initiator ports for fibre). This enables the original
RCUs to send TC390 remote copy operations to the original MCUs to bring the original M-VOLs up to
date. If SVP 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.
CAUTION: Before issuing the CESTPATH command, verify that the relevant paths are offline from
the host(s) (for example, configure the Chipid offline, 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
(LCP/RCP) cannot be changed.
8. At the remote site, establish the same TC390A groups and TC390 pairs in the reverse direction to
synchronize the original M-VOLs with the R-VOLs. Make sure to use the Entire TC390 initial copy option.
The following table shows the correct timer types for performing TC390A operations in the reverse
direction.
Resuming Normal Operations at the Main Site
After the TC390 pairs have been established in the reverse direction, you are ready to resume normal
operations at the main site. Remember that the TC390 terminology is now reversed: the original RCUs and
R-VOLs (remote site) are now the MCUs and M-VOLs, and the original MCUs and M-VOLs (main site) are
now the RCUs and R-VOLs.
To resume normal operations at the main site:
1. At the remote site, verify that all TC390 pairs are in the duplex state. This indicates that the TC390
initial copy operations are complete.
2. Halt the applications at the remote site and vary the M-VOLs (original R-VOLs) offline at the remote site.
This maintains synchronization of the TC390 Synchronous pairs.
3. At the remote site, suspend all TC390 pairs at the MCUs (original RCUs) to destage any pending data
from cache. Confirm that the pairs are suspended before proceeding. If an error occurs, resolve it
before proceeding.
4. At the remote site, delete all TC390 pairs at the MCUs (original RCUs) using the Delete All Pairs option
for TC390 sync pairs and the Delete-Group option for TC390A pairs. For TC390A pairs, the MCU and
RCU complete all pending updates before changing the pair status to simplex.
5. At the remote site, change the TC390 settings at the MCUs (original RCUs) to prepare for normal
TC390 operations. Delete the TC390A groups and the RCUs (original MCUs). If you plan to use the
same remote copy connections, reconfigure the ports (change RCPs back to LCPs for serial, change
initiator ports back to ordinary target ports for fibre). If SVP 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 main site.
Table 25 Selecting the correct timer type for TrueCopy Async disaster recovery
Original Configuration Timer Type for Copy Back
MCU-RCU Configuration Timer Type I/O Time-Stamp Function at
Secondary System?
Yes
No
n-to-1 (n>1) System None None
1-to-1 System System None
Local Local Local