HP StorageWorks XP Remote Web Console Software User Manual
Page 140
Asynchronous Parameters:
•
Delete Range: The delete range option simplifies disaster recovery operations for XP Continuous
Access Asynchronous consistency groups at the RCU (secondary (remote) storage system).
◦
Group (MCU or RCU): All pairs in the same consistency group(s) as the selected pair(s)
will be released, regardless of the pair status and consistency status. You must select only
one pair in each consistency group.
If you release (pairsplit-S) the XP Continuous Access Asynchronous pair from the RCU
with the Group option, while the P-VOL continues accepting I/Os, the XP Continuous
Access Asynchronous pair is forcibly suspended. This suspend is due to the S-VOL failure
(not user-requested). This status is temporary, and will change to SMPL finally. In this case,
it is possible that all pending recordsets are not settled.
CAUTION:
Do not use this option when releasing pairs at the RCU during a disaster
recovery.
◦
C/T (RCU only): The RCU will release all XP Continuous Access Asynchronous pairs that
have the consistency status of group.
◦
LU (MCU or RCU): The MCU/RCU will release only the specified XP Continuous Access
Asynchronous pair(s). This option can be used to remove individual LUs from consistency
groups.
For the LU delete range setting, if you select pairs with PAIR status and other than PAIR
status in the same consistency group, an unexpected suspend may occur during the pair
operations (Pairsplit-r, Pairsplit-S, and Pairresync) under heavy I/O load conditions. You
can estimate whether or not the I/O load is heavy from the rate of the sidefile cache
(around 30%) or, if you cannot see the sidefile cache rate, from the frequency of host
I/O. The release pair operations should be performed under light I/O load conditions.
The default delete range settings are:
◦
Two or more pairs in a group are selected: LU.
◦
One pair is selected in each group and one or more P-VOLs are selected: Group.
◦
One pair is selected in each group and all selected volumes are S-VOLs: C/T.
When the Delete Pair By Force option is selected for an asynchronous pair, the Delete Range
option is set to Group to protect the integrity of the consistency group. This ensures that one
or more pairs in a consistency group cannot be forcibly released.
To release one or more XP Continuous Access pairs:
1.
Connect to the MCU or RCU* of the pair(s) to be released, open the XP Continuous Access
main window, and click the Pair Operation tab.
If you plan to use the C/T Delete Range option, you must connect to the RCU.
2.
In the tree, select a port, host group, desired CU, or upper CU grouping. Use the Display Filter
as needed to display the desired pairs (for example, select Async only) (see
).
3.
In the list, select the pair(s) that you want to release.
Select either XP Continuous Access Synchronous or XP Continuous Access Asynchronous pairs
(not both). If you plan to use the C/T or Group delete range option, select only one XP
Continuous Access Asynchronous pair in the group.
4.
Right-click, and click Pairsplit-S to open the Pairsplit-S dialog box (see
for Synchronous and Asynchronous Pairs” (page 139)
).
5.
On the Pairsplit-S dialog box, select the desired pair release options, and click Set to close
the Pairsplit-S dialog box. The preview list displays the requested pairsplit-S operation(s).
140 Performing XP Continuous Access Pair Operations