Difference Management; Pair Status - HP StorageWorks P9000 User Manual

Continuous access journal for mainframe systems user guide
Hide thumbs Also See for StorageWorks P9000:
Table of Contents

Advertisement

The primary system copies the P-VOL VOLSER back to the S-VOL when the pair is resumed. When
the S-VOL read option is not enabled and/or the pair is not suspended, the secondary system
rejects read and write I/O to a S-VOL.

Difference management

Differential data (updates during split or suspension) between the P-VOL and S-VOL is stored in a
track bitmap. When a split/suspended pair is resumed, the primary system merges the P-VOL and
S-VOL bitmaps, and the differential data is copied to the S-VOL.
The number of bitmap areas affects the maximum possible number of pairs that can be created in
the storage system.

Pair status

Every pair operation results in a change in pair status. You should monitor pair status to insure
that an operation completed successfully. Also, pairs must have a specific status in order for specific
operations to be executed.
The following provides a brief description of the pair statuses. For complete details, see
definitions" (page 80)
Simplex: A volume that is not assigned to a pair.
Duplex: When a pair is in the process of being created, the primary system changes the status
of the P-VOL and S-VOL to Pending Duplex.
When the initial copy operation is complete, the primary system changes the status of both
data volumes to Duplex.
Pending: The initial copy operation for this pair is in progress. This data volume pair is not
yet synchronized.
When the initial copy operation is complete, the primary system changes the status of both
data volumes to Duplex.
Duplex: This data volume pair is synchronized. Updates to the P-VOL are duplicated on the
S-VOL.
When the initial copy operation is complete, the primary system changes the status of both
data volumes to Duplex.
Suspended When a pair is split from the primary system, the primary system changes the
status of the P-VOL and S-VOL (if the path status is normal) to Suspended.
When a pair is suspended from the secondary system, it changes the S-VOL status to
Suspended. The primary system detects the pair suspension (if the path status is normal) and
changes P-VOL status to suspended.
When you release (delete) a pair from the primary system, that system changes the status of
the P-VOL and S-VOL (if the path status is normal) to simplex.
When you release a pair from the secondary system, that system changes S-VOL status to
Simplex. The primary system detects the pair release (if the path status is normal) and changes
P-VOL status to Suspended.
16
Continuous Access Journal Z overview
.
"Pair status

Advertisement

Table of Contents
loading

This manual is also suitable for:

Storageworks p9500

Table of Contents