HP StorageWorks XP Remote Web Console Software - Manual (Page 173)

if you use the CESTPATH command to add the pairs at the secondary site. 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 TrueCopy for Mainframe operations in
the reverse direction (change RCU target ports to initiator ports for fibre). This enables the
original RCUs to send TrueCopy for Mainframe 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.
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) (for example, 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.
8. At the remote site, establish the same TrueCopy for Mainframe Asynchronous groups and
TrueCopy for Mainframe pairs in the reverse direction to synchronize the original M-VOLs
with the R-VOLs. Make sure to use the Entire Volume TrueCopy for Mainframe initial copy
option.
“Selecting the Correct Timer Type for TrueCopy for Mainframe Async Disaster Recovery”
(page 173) shows the correct timer types for performing TrueCopy for Mainframe Asynchronous
operations in the reverse direction.
Table 51 Selecting the Correct Timer Type for TrueCopy for Mainframe Async Disaster Recovery
Timer Type for Copy Back Original Configuration
I/O Time-Stamp Function at Secondary System?
No Yes Timer Type MCU-RCU Configuration
None None System n-to-1 (n>1)
None System System 1-to-1
Local Local Local
Resuming Normal Operations at the Main Site
Once the TrueCopy for Mainframe pairs have been established in the reverse direction, you are
ready to resume normal operations at the main site. Remember that the TrueCopy for Mainframe
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, make sure that all TrueCopy for Mainframe pairs are in the duplex state.
This indicates that the TrueCopy for Mainframe 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 TrueCopy for Mainframe Synchronous pairs.
Using TrueCopy for Mainframe for Disaster Recovery 173