HP StorageWorks XP Remote Web Console Software - Manual (Page 40)

40 Hitachi TrueCopy z/OS for HP XP12000/XP10000 and SVS 200 storage systems
following records are marked in the cylinder bitmap as modified (to be copied during the resume pair
operation):
• The recordsets that were created by the MCU but not yet sent to the RCU. After marking these cylinders
as modified, the MCU discards these recordsets.
• The recordsets that were sent to the RCU but not acknowledged by the RCU. The MCU marks these
M-VOL cylinders as modified and discards these recordsets. This ensures that recordsets that are lost
during transmission to the RCU are identified and marked.
• The recordsets that reached the RCU but have not yet been settled. After marking these cylinders as
modified, the RCU discards these recordsets.
• The M-VOL records updated by host-requested write I/Os after the volume pair was suspended (same
function as for TC390 Synchronous pairs).
When a suspended TC390A pair is resumed (resynchronized), the contents of the RCU’s cylinder bitmap
are sent to the MCU and merged into the MCU’s cylinder bitmap. The MCU then performs the resync copy
operation according to the merged bitmap. This ensures that all cylinders containing recordsets that were
discarded are resynchronized at this time.
PPRC support
An XP12000/XP10000 with TC390 installed supports IBM PPRC host software functions. You can perform
most TC390 operations by issuing PPRC TSO (or ICKDSF PPRCOPY) commands from the host system
console to the XP12000/XP10000. Using PPRC commands, you can establish and delete remote copy
communication paths; establish, suspend, resume, and delete TC390 Synchronous and TC390A
pairs/groups; and view TC390 path and pair status. For more information on using PPRC TSO and
ICKDSF commands with the XP12000/XP10000, see ” Using PPRC commands for TrueCopy ” on
page 157.
For operating systems that do not support PPRC, TC390 through XP Command View Advanced Edition
Software or XP Remote Web Console is used to control and monitor TC390 operations. In this case, TC390
provides only state-change-pending (SCP) notifications with service information messages (SIMs).
Restrictions. If you plan to use PPRC commands instead of the TC390 software to perform TC390
operations, the following restrictions apply:
• SVP system option mode 114 (see Table 3 on page 18) must be enabled to allow automatic port
configuration in response to PPRC commands. To fully support an automated environment, the
XP12000/XP10000 is capable of automatically configuring a serial port as an RCP or LCP, or a Fibre
Channel port as an initiator or RCU target port if required in response to the TSO CESTPATH and
CDELPATH commands. However, even if you set ON for SVP system option mode 114, initiator ports will
not automatically change to RCU target ports, nor vice versa, when these ports are in initiator/external
mix mode. The XP12000/XP10000 will verify that the specified MCU port is offline to the host and will
automatically configure it as an RCP or initiator port if required. Similarly, the corresponding RCU port
will also be configured as an LCP or RCU target port if required. When the CDELPATH command is
issued, the TC390 logical paths are removed, and if there are no more TC390 or TC logical paths on
the port, the port is automatically changed from RCP mode to LCP mode, or from initiator port mode to
RCU target port mode.
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 Management. 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, 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.