There are different types of SnapMirror available to you. However, the different types of SnapMirror cannot be used at different stages in a cascade.
The supported cascading configurations are listed in the following table. Any other configuration, such as extending the cascade beyond the number of cascades shown in the table, is not supported.
Note: This limitation does not apply to the strictly asynchronous volume
SnapMirror cascading configuration, which can propagate to more than three
storage systems.
Table 1. Two-hop cascade configurations supported. The following table lists the supported two-hop cascade configurations supported for SnapMirror replication.| Storage system A to Storage system B |
Storage system B to Storage system C |
|---|
| Synchronous SnapMirror (volume) |
Asynchronous SnapMirror (volume) |
| Asynchronous SnapMirror (volume) |
Asynchronous SnapMirror (volume) |
| Asynchronous SnapMirror (volume) |
Asynchronous SnapMirror (qtree) |
| Asynchronous SnapMirror (qtree) |
Asynchronous SnapMirror (volume) |
This table should be read from left to right.
Example
The first line states that
Storage system A has a synchronous
SnapMirror relationship with
Storage system B, and that
Storage system B has an asynchronous volume
SnapMirror relationship with
Storage system C.
You can cascade volume destinations from a synchronous
SnapMirror destination, but the cascading series is slightly different from that for asynchronous
SnapMirror. For a synchronous
SnapMirror, the first replication is the only synchronous
SnapMirror replication in the cascade, and the synchronous replication can be to one destination
storage system only. Subsequent
SnapMirror replications cascading from that destination system must be asynchronous and can be to multiple destination systems.
