If you are sharing Thin Image P-VOLs with ShadowImage, Universal Replicator, or TrueCopy S-VOLs within a storage system, you can use consistency group pair-split to split the pairs that are defined in a consistency group to store the snapshot data. Consistency group pair-split maintains consistency for the Thin Image S-VOLs that are defined in the consistency group.
The following figures illustrate these configurations.
The following figure shows the consistency group pair-split configuration when you are sharing Thin Image P-VOLs with Universal Replicator S-VOLs.
The following figure show the consistency group pair-split configuration when sharing Thin Image P-VOLs with TrueCopy S-VOLs.
The following table explains when you can use consistency group pair-split with shared volumes.
|
HTI P-VOL used as |
Pair status |
Can you use consistency group pair-split? |
|---|---|---|
|
UR S-VOL |
COPY |
No |
|
PAIR |
Yes |
|
|
PSUS |
Yes |
|
|
TC S-VOL |
COPY |
No |
|
PAIR |
Yes |
|
|
PSUS |
Yes |
|
|
SI S-VOL |
COPY |
No |
|
PAIR |
No |
|
|
COPY(SP) |
No |
|
|
PSUS(SP) |
No |
|
|
PSUS |
Yes |
|
|
COPY(RS) |
No |
|
|
COPY(RS-R) |
No |
|
|
PSUE |
No |
You cannot maintain the consistency of Thin Image S-VOLs that are defined in a consistency group in the following cases:
- You are sharing a Thin Image P-VOL with ShadowImage, TrueCopy, or Universal Replicator S-VOLs, and the statuses of those pairs are not the same.
- You are sharing a Thin Image P-VOL with a Universal Replicator S-VOL and they do not share the same journal.
For more information about Universal Replicator, see the Hitachi Universal Replicator User Guide.