HP StorageWorks XP Remote Web Console Software - Manual (Page 140)

Changing from 3990 to 2105 or 2107: If you need to change the emulation from 3990 to 2105
or 2107 for an HP disk array which has existing Compatible XRC and/or Concurrent Copy (CC)
pairs, you must:
1. Stop all Concurrent Copy jobs and release all Compatible XRC pairs.
2. Change the CU emulation type of all CHA packages in the HP disk array to 2105 or 2107.
For Compatible XRC and CC operations, 3990 and 2105 or 2107 emulations cannot be
intermixed in the same storage system.
3. Restart Concurrent Copy jobs and re-establish Compatible XRC pairs.
The PPRC commands are different for 3990 and 2105 or 2107 emulation types.
MCU is XP disk array, and the host on the MCU side is connected to the package of 2105 or
2107 CU emulation type.
Powering Off/On TrueCopy for Mainframe Components
The user is responsible for controlling power-off activities for storage systems involved in TrueCopy
for Mainframe operations. If you need to power off the XP disk array, call your HP representative
or the HP technical support for assistance.
If power is removed from an MCU while TrueCopy for Mainframe operations are in progress, the
TrueCopy for Mainframe pairs are not affected, but the update sequence consistency of the TrueCopy
for Mainframe Asynchronous groups at the RCU may be affected. When power is restored to an
MCU, the MCU communicates with its RCU(s) to confirm the pair status of the R-VOLs. Make sure
that TrueCopy for Mainframe communications are fully restored (all RCU paths have normal status)
before beginning I/O operations to the M-VOLs. If the MCU accepts a write I/O operation for an
M-VOL before this confirmation is complete, the MCU will suspend the pair and change the status
of the M-VOL to suspended-by RCU (the MCU will not be able to change the pair status of the
R-VOL).
If power is removed from an RCU or remote copy connection while TrueCopy for Mainframe
operations are in progress, the MCU(s) will detect the communication failure, suspend all affected
pairs, and generate SIMs and console messages reporting the failures. The MCU will change the
status of the M-VOLs to suspended-by RCU but will not be able to change the status of the R-VOLs.
If an MCU/RCU is powered off and its backup batteries are fully discharged while TrueCopy for
Mainframe pairs are suspended, the M-VOL/R-VOL cylinder maps will not be retained. In this
unlikely case, the MCU/RCU will mark all cylinders of all suspended TrueCopy for Mainframe
volumes as modified, so that the MCU will perform the equivalent of an entire initial copy operation
when the pairs are resynchronized. (The R-VOL cylinder map is used only for TrueCopy for
Mainframe Asynchronous operations.)
Planned Outage of the MCU
A planned MCU outage does not affect TrueCopy for Mainframe Synchronous pairs. For TrueCopy
for Mainframe Asynchronous operations, the MCU must communicate with the RCU even when
there are no M-VOL update I/Os from the primary system. During the power-off sequence, the
MCU will automatically suspend all TrueCopy for Mainframe Asynchronous pairs in the duplex
and pending duplex state (suspend type = MCU P/S-OFF). During power-on-reset sequence, the
MCU will automatically resynchronize these suspended pairs (pairs with other suspend types are
not automatically resynchronized).
If a TrueCopy for Mainframe Asynchronous group contains M-VOLs in the MCU being powered
off and in other MCU(s) which is/are not being powered off, the pairs behind the other MCU(s)
will not be suspended and will continue to be updated. If you need to maintain a fully consistent
group at the RCU during the planned MCU outage, take the following steps:
1. Quiesce the applications using all M-VOLs in the consistency group.
2. Suspend the group at the RCU using the Group suspend option. You can use the Purge or
Drain suspend option since the M-VOL updates have stopped.
140 Performing TrueCopy for Mainframe Configuration Operations