HP XP Continuous Access Software - Manual (Page 40)

Table 7 Consistency Status for Split/Suspended XP Continuous Access Journal Secondary
Data Volumes (continued)
Description Consistency Status (shown
at secondary storage
system)
Access Journal data volume pair from the secondary storage system). This
status is indicated when:
•
This pair was split by the user using the Suspend Range-Group pairsplit
option.
•
All pairs in this journal group were suspended due to a failure that affected
the entire journal group (not just one pair). For example, a primary storage
system to secondary storage system communication failure.
Suspend Types
Table 8 (page 40) lists and describes the XP Continuous Access Journal suspend types, which
indicate the reason for the suspension. XP Continuous Access Journal pairs can be suspended by
either the primary storage system or secondary storage system. For further information on XP
Continuous Access Journal suspension conditions, see
“Suspension Conditions” (page 41) .
The primary storage system suspends an XP Continuous Access Journal pair when it detects any
of the following suspension conditions:
•
The user has released the data volume pair from the secondary storage system.
•
An error condition occurred related to the secondary storage system, secondary data volume,
or an XP Continuous Access Journal update copy operation.
•
The system is unable to communicate with the secondary storage system.
•
The system detects an XP Continuous Access Journal suspension condition.
When an XP Continuous Access Journal pair is suspended, the primary storage system stops
performing journal obtain operations for the pair. Even though some operations are stopped, the
primary storage system continues the following operations:
•
Continues accepting write I/Os for the suspended primary data volume.
•
Keeps track of the primary data volume cylinders/tracks that are updated while the pair is
suspended.
•
Keeps track of any journal data that was discarded during the pair suspension. (Both the
primary and secondary storage systems do this).
When the suspended XP Continuous Access Journal pair is resumed (pairresync), the primary and
secondary storage systems perform the following operations:
•
The secondary storage system sends the secondary data volume bitmap to the primary storage
system.
•
The primary storage system merges the primary data volume and secondary data volume
bitmaps to determine which cylinders/tracks are out-of-sync.
•
The primary storage system merges the primary data volume and secondary data volume
bitmaps to identify the out-of-sync cylinders/tracks.
This method ensures that all cylinders/tracks that contain journal data that was discarded at the
secondary storage system are resynchronized at this time.
Table 8 Suspend Types (PSUE)
Description Applies to Type
The primary storage system detected an error during a secondary
storage system communication or an error during an update copy. Primary data volume,
Secondary data volume PSUE, S-VOL
Failure
40 About XP Continuous Access Journal Operations