HP StorageWorks XP24000 Continuous Access Journal Software User and Reference Guide, v01 (T5278-96001, June 2007)

• Range: Allows you to specify the release range. The default is LU if two or more pairs in the same
consistency group are selected. The default is Group if not. Also, if the pair status is SMPL, Range
is set
to LU. If the pair status is De l eting or Suspending, Range is set to Group.
• LU: Only the specified pair(s) will be released.
Note: If you select pairs with both PAIR status and other than PAIR status in the same
consistency group, an unexpected suspension may occur during the pair operations (Pairsplit-r,
Pairsplit-S, and Pa irresync) under heavy I/O load conditions. You can estimate whether
the
I/O load is heavy or not from frequency of host I/Os. The pair operations should be
performed u nder light I/O load conditions.
• Group: All pairs in the same consistency group(s) as the selected pair(s) will b e released.
Caution: Do not use this op tion when releasing pairs at the secondar y storage system during
disaster recovery.
Note: If the following two conditions are satisfied and you select Apply,awarningmessage will
be
displayed and processing cannot be continued:
•The Preview list contains two or more pairs belonging to the same consistency g roup.
•The Range column displays Group forat least oneofthe abovepairs.
To continue processing, do either of the following:
• Ensure that the Range c olumn displays LU for all pairs in the same consistency group.
•In the Preview list, select all but one pair in the same consistency group, right click the selected
pairs, and then select Del ete .
• Delete M ode: Allows you to specify whether to release the pair(s) forcibly. When the status
of the pair(s) to be released is SMPL or Deleting, the default setting is Force. Other wise, the
default setting is Normal.
• Force: The pa ir(s) will forcibly be released even if the primary storage system is unable to
communicate with the secondary storage system. This option may be used to free a host
waiting for device-end from a primary storage system that cannot communicate with its the
secondary storage system, thus allowing host operations to continue.
If
you specify Force when the pair status is other than SMPL, Range will be set to Group.
• Normal: The pair(s) will be released only if the primary storage system is able to change the
pair
status of the primary and secondary data volumes to SMPL.
•
Set: Applies the settings to the Preview list in the Pair O peration window (Figure 3 7 on page 81).
• Cancel:Discards the settings.
Creating a Point-in-Time Copy of Data Volumes
Continuous Access Journal enables you to make Point-in-Time (PiT) duplicates of g roups of volumes. The
term Point-in-Time (PiT) refers to an act of obtaining a copy of data immediately when you want to
obtain
it. Continuous Access Journal can be used to create a PiT copy of data volumes belong ing to
ajour
nal group.
To pro
duce a
PiT duplicate of data volumes belonging to a journal group:
1. Stop
all
write I/Os from hosts to primary data volumes in the journal group.
2. Afte
r
all write I/Os to the primary data volume have stopped, split the
mirror (that is, a pair of the master and restore journal group. See
“Splitting a Mirror (Pairsplit-r: Suspending a Copy Operation)”onpage122).
When
splitting it, use the Pairsplit-r window and then specify Group for Range and specify
Flush for Suspend Mode.
3. Wh
en the
status of a ll data volume pairs in the journal group has changed to PSUS,the
du
plicate set of volumes is complete. If desired, you can restart your business app lication at
the
primary site to resume business activities.
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