Consistency and snapshot groups
Consistency groups and snapshot groups are groups of pairs for which you can simultaneously perform pair tasks on all pairs within the group.
A consistency group can include HTI and SI pairs. Use consistency groups to split the HTI pairs that are defined in the group. Splitting the pairs using the group assures data consistency at the time the VSP G200, G400, G600 storage system receives the request.
A snapshot group is a group of only HTI pairs. Use consistency or snapshot groups to perform HTI tasks on all of the pairs within the group. You define HTI pairs to a snapshot group when you create the pairs.
The following table shows the differences between consistency groups and snapshot groups.
|
Item |
Consistency group |
Snapshot group |
|---|---|---|
|
Pair limit per group |
8,192 |
8,192 |
|
Limit |
2,048 |
2,048 |
|
Data consistency |
Guaranteed |
Not guaranteed |
|
VSP G200, G400, G600 storage system software application from which you can define pairs |
HTI and SI |
HTI |
Related topics
For more information about defining TC pairs in consistency groups, see Hitachi TrueCopy® User Guide.
For more information about defining UR pairs in consistency groups, see Hitachi Universal Replicator User Guide.
For more information about defining SI pairs in consistency groups, see Hitachi ShadowImage® User Guide.