Oracle MaxRep for SAN

Oracle MaxRep for SAN enables you to replicate and restore Oracle FS System data in a SAN environment.

In SAN replication, pairs of LUNs that are made up of source LUNs and target LUNs, are called replication pairs. The LUNs can reside on two Oracle FS Systems in a single location or on separate remotely distributed Oracle FS System, designated as primary and secondary.

One or more Oracle MaxRep Replication Engines manage and monitor the data replication process. The transfer of data takes place automatically as the data on the source LUN changes. Those changes are replicated to the target LUN. The replication pair updates continuously as long as the integrity of both LUNs persists and the communication link between the LUN locations is maintained.

Oracle MaxRep for SAN can replicate between Oracle FS Systems that reside in the same data center, or are geographically distributed between remote locations. The Oracle MaxRep Replication Engines use communication links between the two sites to replicate changes.

Oracle MaxRep for SAN supports synchronous and asynchronous LUN replication or application consistent volume sets.

Synchronous replication requires at least one Replication Engine and is supported when the source LUN, the target LUN, and the Replication Engines are all attached to the same SAN fabric. Replication can also be synchronous when the source LUN and the target LUN are located in two data centers that are connected by an extended SAN fabric. The fabric might consist of fiber optic cables that uses dense wavelength division multiplexing (DWDM) between the primary and secondary locations.
Asynchronous replication requires at least two Replication Engines. Asynchronous replication is supported in most cases when the primary and secondary locations are geographically distributed, and communication is over a wide area network (WAN) link, with separate Replication Engines at each location.

To ensure high availability (HA), Replication Engines can be deployed in HA pairs. One of the Replication Engines is in active mode. The other Replication Engine in the HA pair is in passive mode, ready to take over if the active Replication Engine should fail.

Figure 1: Asynchronous Oracle MaxRep for SAN configuration

Legend

1 Primary site	5 Primary Oracle FS System
2 Secondary site	6 Secondary Oracle FS System
3 WAN connection	7 Replication Engines on the primary site clustered for high availability
4 Host	8 Replication Engines on the secondary site clustered for high availability

Data can be recovered from either the primary or the secondary site, and the direction of replication can be reversed. Several failover and failback scenarios can be planned and implemented using Oracle MaxRep for SAN.