Replication modes for Remote Copy
The replication modes for Remote Copy volume groups are:
| Replication mode | Difference between other modes | RPO |
Synchronous (sync): Synchronous mode volume groups stay synchronized as long as the replication links remain up and available.
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Data concurrency is greater than in asynchronous periodic mode or asynchronous streaming mode, but host write I/O response times may be higher than in asynchronous periodic or asynchronous streaming mode. | RPO is 0. |
Asynchronous periodic (periodic): Asynchronous periodic mode volume groups resynchronize at specific intervals using snapshots.
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Host I/O write response times can be better than in synchronous mode, but data is not always in sync. | For properly sized replication links, the RPO is 2 times the replication period chosen for the Remote Copy group (minimum of 10 minutes). |
Asynchronous streaming (async): Asynchronous streaming mode volume groups replicate data to the secondary system constantly.
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Data concurrency is greater than asynchronous periodic mode, but not as good as synchronous mode. Host I/O write response times can be better than synchronous mode. | For properly sized replication links, the maximum RPO is 2 minutes. |