HP XP Continuous Access Software User Manual

Page 39

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Tracking Journal Data: The primary storage system and secondary storage system keep track of
any journal data that was discarded during the pairsplit operation. After the pair status changes
to PSUS, the primary storage system performs the following tasks:

Stops performing journal obtaining operations for the pair

Continues accepting write I/Os for the split XP Continuous Access Journal primary data volume

Keeps track of the primary data volume tracks which are updated while the pair status is split

If you enabled the secondary data volume write option when you split the pair, the secondary
storage system keeps track of the secondary data volume tracks that are updated while the pair
is split.

Resume Pair – Synchronization: When the pair is resumed (pairresync), the secondary storage
system sends the secondary data volume track bitmap to the primary storage system, and the
primary storage system merges the primary data volume and secondary data volume bitmaps to
determine which tracks are out-of-sync.

Consistency Status: A split (or suspended) XP Continuous Access Journal secondary data volume
has an additional status called the consistency status. The consistency status appears only at the
secondary storage system and indicates the update sequence consistency of the secondary data
volume with respect to the other secondary data volume in the same group.

Table 7 (page 40)

lists

and describes the consistency statuses shown at the secondary storage system for split or suspended
XP Continuous Access Journal secondary data volumes.

Table 6 XP Continuous Access Journal Split Types (PSUS)

Description

Applies to

Type

The secondary data volume split type is PSUS-by MCU.

Primary data volume

PSUS, P-VOL by
Operator

The user split the pair from the primary storage system or
secondary storage system using the secondary data volume
option.

Primary data
volume, Secondary
data volume

PSUS, S-VOL by
Operator

The secondary storage system received a request from the
primary storage system to split the pair. The primary data volume
split type is PSUS-P-VOL by Operator or PSUS-S-VOL by
Operator.

Secondary data
volume

PSUS, by MCU

The primary storage system detected an error condition at the
secondary storage system that caused the primary storage system
to suspend the XP Continuous Access Journal data volume pair.
The secondary data volume suspend type is PSUE-S-VOL Failure.

Primary data
volume, Secondary
data volume

PSUS, by RCU

The primary storage system detected that the secondary data
volume status changed to SMPL because the user released the
pair (pairsplit-S) from the secondary storage system. The pair
cannot be resumed because the secondary data volume does
not have the PSUS/PSUE status.

Primary data volume

PSUS, Pairsplit-S to
RCU

The data volume pair was suspended because it was highly
likely that journal data overflows.

NOTE:

RAID Manager displays this split type as PFUS.

Primary data
volume, Secondary
data volume

PSUS, JNL Cache
Overflow

Pair Status

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