Recovering from a P-VOL failure (LDEV blockade) at the source GAD primary site

Global Active Device for VSP One Block

Version

10.5.x

File Size

25537 KB

Audience

anonymous

Part Number

MK-23VSP1B011-11

ft:lastEdition

2026-06-23

The procedure for recovering from a failure in the P-VOL (LDEV blockade) of the source GAD pair changes the pair status back to the status during migration to the target GAD+UR environment. If a failure (LDEV blockade) occurs in the P-VOL at the source GAD primary site, the pair status of the GAD pair changes to PSUE/SSWS and delta resync is automatically performed.

If a failure occurs in the LDEV at the source primary site (failure in the P-VOL of the source GAD pair), delta resync is performed at the source site.
If no failure occurs in a pair, the pair status remains unchanged.
The pair status for the P-VOL and S-VOL of the different pairs will be as follows:
- For the source UR pair: Changes to the UR delta resync pair.
- For the source GAD pair: PSUE for the P-VOL and SSWS for the S-VOL
- For the source UR delta resync pair: Changes to the normal UR pair (changes from COPY to PAIR for both P-VOL and S-VOL)
- For the temporary GAD pair for migration: PSUE(Local) for the P-VOL and PSUE(Block) for the S-VOL, or COPY for both P-VOL and S-VOL
Note: If there are no I/Os issued to the failure location, the pair status remains COPY.
Delete the target UR pair.
Command example:
```
pairsplit -g UR10 -S -IH11
```
Delete the target UR delta resync pair.
Command example:
```
pairsplit -g UR11 -S -IH12
```
Suspend the target GAD pair.
Command example:
```
pairsplit -g HA10 -IH11
```
Delete the target GAD pair.
Command example:
```
pairsplit -g HA10 -S -IH11
```
If the temporary GAD pair used for migration is not suspended, suspend the temporary GAD pair.
Command example:
```
pairsplit -g HA20 -IH01
```
Delete the temporary GAD pair used for migration.
Command example:
```
pairsplit -g HA20 -S -IH01
```
Delete the source UR pair linked with the LDEV for which LDEV blockade occurred.
Command example:
```
pairsplit -g UR01 -d dev020 -S -IH02
```
Delete the source UR delta resync pair linked with the LDEV for which LDEV blockade occurred.
Command example:
```
pairsplit -g UR00 -d dev010 -S -IH01
```
Delete the source GAD pair linked with the LDEV for which LDEV blockade occurred by specifying the S-VOL.
Command example:
```
pairsplit -g HA00 -d dev000 -R -IH02
```
Recover the LDEV blockage.
If a consistency group contains a source GAD pair that uses a not-blocked LDEV, swap resync the source GAD pair.
Command example:
```
pairresync -g HA00 -swaps -IH02
```
At the secondary site, re-create the GAD pair that was deleted in step 10.
Command example:
```
paircreate -g HA00 -d dev000 -fg never 0 -vl -jq 0 -IH02
```
Re-create the UR delta resync pair that was deleted in step 9.
Command example:
```
paircreate -g UR00 -d dev010 -async -vl -jp 0 -js 2 -nocsus -IH01
```
Create the UR pair that was deleted in step 8.
Command example:
```
paircreate -g UR01 -d dev020 -f async -vl -jp 1 -js 2 -IH02
```
Confirm that the pair status of the source UR delta resync pair changes to PSUS after update I/O is issued to the source GAD pair.
Swap the P-VOL and S-VOL of the source GAD pair.
Command example:
```
pairresync -g HA00 -swaps -IH01
```
Confirm that the pair status of the source UR delta resync pair changes to PSUS after update I/O is issued to the source GAD pair.
Retry migration procedures by referring to GAD+UR pair migration workflow.