HP StorageWorks XP Remote Web Console Software - Manual (Page 34)

34 Overview of Continuous Access XP Journal
Continuous Access XP Journal split types (PSUS)
Table 5 describes Continuous Access XP Journal split types. You can split a Continuous Access XP Journal
pair any time after the initial copy operation completes. You must split a Continuous Access XP Journal
pair to perform media maintenance on the primary data volume or access the secondary data volume
(secondary data volume write enable).
When splitting a Continuous Access XP Journal pair, the primary and secondary arrays ensure
synchronization by completing or discarding pending update copy operations according to the
user-specified pending update option (purge/flush). The primary and secondary arrays keep track of
journal data discarded during the pairsplit operation. After the pair status changes to PSUS, the primary
array stops performing journal obtain operations for the pair, continues accepting write I/Os for the split
Continuous Access XP Journal primary data volume, and keeps track of primary data volume tracks
updated while the pair status is split. If you enabled the secondary data volume’s write option when
splitting the pair, the secondary array keeps track of the secondary volume tracks updated while the pair
is split. When the pair is resumed (pairresync), the secondary array sends the secondary data volume’s
track bitmap to the primary array, and the primary array merges the primary and secondary data volume
bitmaps to determine which tracks are out-of-sync.
A split (or suspended) Continuous Access XP Journal secondary data volume has an additional status
called the consistency status. The consistency status is displayed only at the secondary array and indicates
the update sequence consistency of the secondary data volume with respect to the other secondary data
volume in the same group. Table 6 describes consistency statuses for split or suspended Continuous
Access XP Journal secondary data volumes (the consistency status is displayed only at the secondary
array).
Suspending Pair is not synchronized and is in transition from
PAIR or COPY to PSUS/PSUE. When the
split/suspend pair operation is requested, the
status of all affected pairs changes to Suspending.
When the split/suspend operation is complete,
the status changes to PSUS/PSUE.
Read / Write Read Only
Deleting Pair is not synchronized and is in transition from
PAIR, COPY, or PSUS/PSUE to SMPL. When the
pairsplit-S operation is requested, the status of all
affected pairs changes to Deleting. When the
pairsplit-S operation is complete, the status
changes to SMPL.
Read / Write Read Only
Table 4 Continuous Access XP Journal data volume pair status (continued)
Pair status Description Primary data
volume access
Secondary data
volume access
Table 5 Continuous Access XP Journal split types (PSUS)
Type Applies to Description
PSUS, P-VOL by
Operator
Primary data volume The secondary data volume’s split type is PSUS-by MCU.
PSUS, S-VOL by
Operator
Primary data volume,
Secondary data volume
You split the pair from the primary or secondary array using
the secondary data volume option.
PSUS, by MCU Secondary data volume The secondary array received a request from the primary
array to split the pair. The primary data volume’s split type
is PSUS-P-VOL by Operator or PSUS-S-VOL by Operator.
PSUS, by RCU Primary data volume,
Secondary data volume
The primary array detected an error condition at the
secondary array that caused the primary array to suspend
the Continuous Access XP Journal data volume pair. The
secondary data volume suspend type is PSUE-S-VOL Failure.