Storage service device with dual controller and backup method thereof

A storage service device with a dual controller, applicable to provide the same view service to an event-login log and a configuration file of a server, the storage service device comprising:

• a first control module, comprising a first memory module and a first flash memory, wherein the first control module stores an index page used for recording an access address of a virtual disk in the storage service device;
• a second control module, electrically connected to the first control module, and comprising a second memory module and a second flash memory, wherein the second control module stores another index page therein;
• a battery unit, electrically connected to the first memory module and the second memory module;
• and
• a basic input/out system (BIOS), electrically connected to the battery unit, the first control module, and the second control module, and comprising a backup procedure, wherein once a power failure occurs to the server, the BIOS executes the backup procedure:
• sending a hardware interrupt signal to the battery unit, so as to provide an operation power to the first memory module and the second memory module;
• synchronizing the index page of the first memory module with that of the second memory module;
• and
• recording updated index pages into the first flash memory and the second flash memory respectively.