You must have two storage arrays.

Each storage array must have two controllers.

The two storage arrays must be discovered in Unified Manager.

Each controller in both the primary array and secondary array must have an Ethernet management port configured and must be connected to your network.

The storage arrays have a minimum firmware version of 7.84. (They can each run different OS versions.)

You must know the password for the local and remote storage arrays.

You must have enough free capacity on the remote storage array to create a secondary volume equal to or greater than the primary volume that you want to mirror.

Asynchronous mirroring is supported on controllers with Fibre Channel (FC) or iSCSI host ports, while synchronous mirroring is supported only on controllers with FC host ports.