HP StorageWorks XP Remote Web Console Software - Manual (Page 106)

pair is split, regardless of the P-VOL fence-level setting. Use this setting to maintain
synchronization of the XP Continuous Access pair.
•
Asynchronous Parameters:
Suspend Range:
Group: The MCU and RCU splits all other XP Continuous Access Async pairs in the same
consistency group as the specified pairs. This option is available only when one pair is
selected.
◦
LU: The MCU and RCU splits only the specified XP Continuous Access Async pairs (even
if error level of the pair is group).
◦ Pending Update:
Drain: The MCU changes the XP Continuous Access Async pair status from Suspending
to PSUS only after the RCU accepts the pairsplit operation and completes the following
steps:
1. Finishes settling all pending recordsets for the pair.
2. Completes negotiation with all MCUs (report ready-for-suspension to all MCUs and
receive acknowledgements) without further recordsets generated.
If the RCU cannot complete these actions within the copy pending timeout setting, the
RCU discontinues the original pairsplit-r request and forcibly suspends affected XP
Continuous Access Async pairs. Thus, you can use the copy pending timeout parameter
to limit the amount of time it takes to complete the split-drain operation.
Purge: The MCU changes XP Continuous Access Async pair status from Suspending to
PSUS as soon as the RCU accepts the pairsplit operation. The MCU and RCU discard
pending recordsets and mark cylinders containing discarded recordsets as modified in
P-VOL and S-VOL bitmaps, respectively. When the pair is resumed (pairresync), the P-VOL
and S-VOL bitmaps are merged at the MCU, and all cylinders marked as modified are
copied to the S-VOL.
If the MCU does not receive acknowledgement of the pairsplit-r operation from the RCU
within the copy pending timeout setting, the MCU forcibly suspends all affected XP
Continuous Access Async pairs.
NOTE: If you select a pair from the volume list and change the settings, and then use a drop-down
list to set a parameter to blanks, the parameter takes the default value for each pair. If you select
settings from the Preset list before applying the changed settings, and then use a drop-down list to
set a parameter to blanks in the Pairsplit-r pane, the parameter value in the Preset list does not
change.
1. Connect to the MCU (or RCU) of the volume pairs to be split. You do not need to vary the
P-VOLs offline. To use the S-VOL write enable option, connect to the MCU, and select the
P-VOL of the pair.
2. From the CU Number/Port Number tree on the XP Continuous Access main pane, click the
number of the correct CU image.
3. From the Volume list on the XP Continuous Access main pane, click the XP Continuous Access
volume pairs to be split. Select either XP Continuous Access Synchronous or XP Continuous
Access Asynchronous pairs, but not both. Pair status must be PAIR.
4. Right-click, and click Pairsplit-r. The Pairsplit-r pane appears.
5. Click the options for the pairs, and click Set to close the Pairsplit-r pane and set parameters.
The list changes to the Pair Settings Parameter list (Pairsplit-r). You can modify options as
needed (see
“Modifying parameters and deleting LUs” (page 96) ). Ensure that pairsplit options
106 Performing XP Continuous Access configuration operations