The pair status and I/O mode of a GAD pair, the accessibility of the server, and the storage location of the latest data depend on the status before a failure occurs.
The following table shows pair status and I/O mode, the volumes accessible from the server, and the location of the latest data before a failure occurs. You can compare this information with the changes that take place after a failure occurs, as described in the following topics.
Pair status and I/O mode |
Volume accessible from the server |
Volume with latest data |
||
|---|---|---|---|---|
P-VOL |
S-VOL |
P-VOL |
S-VOL |
|
PAIR (Mirror (RL)) |
PAIR (Mirror (RL)) |
OK |
OK |
Both P-VOL and S-VOL |
PAIR (Mirror (RL)) |
PAIR (Block) |
OK |
NG |
Both P-VOL and S-VOL |
COPY (Mirror (RL)) |
COPY (Block) |
OK |
NG |
P-VOL |
PSUS/PSUE (Local) |
SSUS/PSUE (Block) |
OK |
NG |
P-VOL |
PSUS/PSUE (Block) |
SSWS (Local) |
NG |
OK |
S-VOL |