PSUS types and behaviors
The PSUS status can be set by the user or the system and from the primary or the secondary system.
|
PSUS type |
Volume PSUS type applies to |
Description |
|---|---|---|
|
PSUS, S-VOL by Operator |
P-VOL, S-VOL |
The user split the pair from the primary or secondary system, using the S-VOL-writeoption. CCI displays this PSUS type as SSWS. |
|
PSUS, by MCU |
S-VOL |
|
|
PSUS, by RCU |
P-VOL, S-VOL |
|
|
PSUS, Pairsplit-S to RCU |
P-VOL |
The primary system detected that S-VOL is unpaired after the user released the pair from the secondary system. The pair cannot be resynchronized. |
|
PSUS, JNL Cache Overflow |
P-VOL, S-VOL |
The pair was suspended because the journal volume was near capacity.
|
A pair can be split after the initial copy is complete.
A pair must be split to perform maintenance on the P-VOL, or to enable write-access on the S-VOL.
After status changes to PSUS, the primary system performs the following tasks:
Stops journal-obtain operations
Continues to accept write I/Os from host to P-VOL
Keeps track of updated P-VOL tracks
If you enable the S-VOL write-option when splitting the pair, the secondary system keeps track of updated S-VOL tracks. When the pair is resynchronized, the secondary system sends the S-VOL track bitmap to the primary system, which then merges P-VOL and S-VOL bitmaps to synchronize the tracks.
A split or suspended S-VOL has a separate consistency status, which indicates the S-VOL’s update sequence consistency with respect to the other S-VOLs in the associated journal. Consistency status displays on the secondary system only. S-VOL consistency status is described below.
S-VOL consistency statuses
|
Consistency status |
Description |
|---|---|
|
Volume |
|
|
Mirror |
- The pair is split using the Split Mirrors window. - All pairs in the associated mirror are suspended due to a failure that affects the entire group; for example, path failure. - One pair in the mirror was suspended due to a failure that did not affect the entire group. |