PSUE types and behaviors
The primary system suspends a pair and changes its status to PSUE when it detects any of the following:
The user has released the pair on the secondary system.
An error condition related to the secondary system, S-VOL, or an update operation.
The primary system is unable to communicate with the secondary system.
A Universal Replicator suspension condition is detected by the system.
The following describes the types of PSUE status.
|
PSUE Type |
Applies To |
Description |
|---|---|---|
|
PSUE, S-VOL Failure |
P-VOL, S-VOL |
The primary system detected an error during communication with the secondary system or during update copying. S-VOL PSUE type is usually PSUE-S-VOL Failure. CCI might display this condition as SSWS. |
|
PSUE, MCU IMPL |
P-VOL, S-VOL |
The primary system could not find valid control information in its nonvolatile memory during IMPL (initial microprogram load). This condition occurs if the primary system is without power for more than 48 hours (power failure and fully discharged backup batteries). |
|
PSUE, Initial Copy Failed |
P-VOL, S-VOL |
The pair was suspended before the initial copy operation was complete. The data on the S-VOL is not identical to the data on the P-VOL. CCI might display this condition as SSWS. |
|
PSUE, MCU P/S OFF |
S-VOL |
The primary system is powered off. CCI displays this condition as SSUS. |
When a pair is suspended, the primary system stops performing journal-obtain operations for the pair but continues to perform the following operations:
Continues accepting write I/Os for the suspended P-VOL
Keeps track of the P-VOL cylinders/tracks that are updated
Keeps track of journal data discarded during the pair suspension. (Both primary and secondary systems do this.)
A split or suspended S-VOL has a separate consistency status that indicates its update sequence consistency with respect to the other S-VOLs in the associated journal. Consistency status is displayed only on the secondary system.
When the pair is resynchronized, the primary and secondary systems perform the following operations:
The secondary system sends the S-VOL bitmap to the primary system.
The primary system merges the P-VOL and S-VOL bitmaps to synchronize the tracks.
These actions ensure that all cylinders/tracks containing journal data discarded on the secondary system are resynchronized.