There is no way to specify a path for the mirror relationship, the port chosen for mirror traffic is determined based on the type of mirroring (synchronous or asynchroumous) and the protocol (FC or iSCSI). Each mirroring method and protocol has its own requirements and restrictions.
Requirements for using synchronous mirroring
Communication for synchronous mirroring is supported only on controllers with Fibre Channel (FC) host ports.
Synchronous mirroring uses the highest numbered FC host port on each controller on both the local storage array and the remote storage array. Controller host bus adapter (HBA) host port 4 is typically reserved for mirror data transmission.
Note: For more information on the requirements for synchronous mirroring please visit the link above.
Requirements for using asynchronous mirroring
Asynchronous mirroring uses the storage array’s host-side I/O ports to convey mirrored data from the primary side to the secondary side.
Note: For more information on the requirements for asynchronous mirroring please visit the link above or review the documentation (pages 15-19) provided in the previous post.