Storage emulator and method thereof

A storage emulator and method thereof are disclosed. The storage emulator allows a host system to access a storage unit connected to a storage system as if the storage unit is directly coupled to the host system. The storage emulator includes a virtual storage emulating module, a storage-managing unit, and a communicating module. The virtual storage emulating module emulates at least one virtual storage unit corresponding to the storage unit on the host system and receives a storage accessing command from the host system. The storage-managing unit identifies the storage accessing command as either a self-sustaining type command or a non-self-sustaining type command. The communicating module communicates with the storage unit of the storage system via the network. If the storage accessing generates a self-sustaining command response in accordance with the storage accessing command and returns the self-sustaining command response to the host system directly. If the storage accessing command is identified as the non-self-sustaining type command, the storage-managing unit forwards the storage accessing command to the storage system via the network, receives a command response in accordance with the storage accessing command from the storage system, and returns the command response to the host system.