Method for enhancing speed of incremental backup, bridge device, and storage system

A bridge device, the bridge device being applicable to a storage system, the storage system comprising a source storage device and a target storage device, the bridge device comprising:

• at least one interface circuit, arranged to couple a host device, the source storage device and the target storage device to the bridge device;
• and
• a processing circuit, coupled to said at least one interface circuit and arranged to control operations of the bridge device for allowing the host device to access the source storage device via the bridge device, perform incremental backup to backup from the source storage device to the target storage device and speed up the incremental backup, wherein:
• regarding a predetermined location within the storage system, the bridge device is arranged to determine whether a record file exists, wherein the record file is used to record information regarding files of the source storage device;
• during an accelerated incremental backup management procedure, in response to the record file existing, the bridge device is arranged to determine whether any file needing to be compared exists, wherein said any file needing to be compared represents at least one file requested by the host device to be written to the source storage device;
• during the accelerated incremental backup management procedure, in response to said any file needing to be compared existing, the bridge device is arranged to compare said any file needing to be compared with content of the record file to generate at least one comparison result, wherein said at least one comparison result indicates whether a set of attributes of said any file needing to be compared completely exist in the record file;
• during the accelerated incremental backup management procedure, the bridge device is arranged to determine whether any difference is found according to said at least one comparison result, wherein it is determined that said any difference is not found if said at least one comparison result indicates that the set of attributes of said any file needing to be compared completely exist in the record file, otherwise, it is determined that said any difference is found;
• and
• during the accelerated incremental backup management procedure, in response to said any difference being not found, the bridge device is arranged to prevent triggering any backup from the source storage device to the target storage device.