The following example shows one way that geographic mirroring can be configured. Node A and Node B are located in New York City. Node C and Node D are located in Boston. All four nodes are configured in the same recovery domain. The production copy can be switched between nodes A and B. The mirror copy can be switched between nodes C and D. Because all of the nodes are in the same recovery domain, the source system in New York can also exchange roles with the target system in Boston, allowing Boston to host the production copy.
This company has defined the following roles for the nodes in the recovery
domain:
In the event of a natural disaster in New York, Node C in Boston becomes
the primary node by upgrading its mirror copy to a production copy. Node C
becomes the source system for geographic mirroring, although geographic mirroring
will be suspended because there is no target node because of the natural disaster
in New York. When the New York site recovers, Node A becomes a backup node
and its previous production copy becomes the mirror copy.
| Node | Role |
|---|---|
| Node A | Primary |
| Node B | Backup 1 |
| Node C | Backup 2 |
| Node D | Backup 3 |