1. A device capable of usage in a storage system including an initiator, a primary target, and a secondary target, the device being capable of configuration for asynchronous remote mirroring functionality and comprising: a target controller capable of communicating with the initiator and performing operations requested by the initiator; and a process on the target controller capable of receiving a stream of command requests from the initiator, performing the requested commands, and asynchronously relaying the requested commands to a secondary target while ensuring precedence graph equivalence between received and relayed commands, the process embedding task attributes in the relayed commands capable of increasing concurrency in commands performed by the secondary target.