HP StorageWorks XP Remote Web Console Software - Manual (Page 143)

Delete Pair by Force:
•
Yes: The pair(s) will be released even if the MCU is unable to communicate with the RCU.
This option may be used to free a host waiting for a device-end from an MCU that cannot
communicate with its RCU, thus allowing host operations to continue.
•
No: The pair(s) will only be released if the MCU is able to change the pair status of the P-VOL
and S-VOL to SMPL.
When the status of the pair(s) to be released is SMPL or Deleting, the default setting is Yes
(which cannot be changed). Otherwise, the default setting is No.
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:
Releasing XP Continuous Access Pairs 143