Data storage system including backup memory and managing method thereof

A managing method for a data storage system which comprises N storage devices and a single backup memory, N being a natural number, each storage device comprising a respective write cache, once said data storage system suffers from power failure, the single backup memory still reserving data stored therein, said managing method comprising the steps of:

• (a) receiving data transmitted from an application I/O request unit;
• (b) executing a predetermined operation for the received data to generate data to be written, wherein the predetermined operation is one selected from the group consisting of an XOR operation, a mirroring operation, a NO operation, a slice operation, a Galois field primitive polynomial operation, and a maximum distance separable code operation over finite fields;
• (c) judging if the storage space of the single backup memory is less than a threshold, or if the addresses in the single backup memory where the data to be written are duplicated are overlapped;
• and if NO in step (c), performing the steps of:
• transmitting the data to be written to the write caches of the N storage devices;
• duplicating the data to be written into the single backup memory;
• and
• in response to a writing confirm message sent from the storage devices, labeling the duplicated data in the single backup memory as being valid.

A data storage system, electrically coupled to an application I/O request unit, comprising:

• N storage devices which each comprises a respective write cache, N being a natural number, the N storage devices selectively outputting a writing confirm message and a flush cache finish message;
• a single backup memory, for reserving data stored in said data storage system once said data storage system suffers from power failure;
• and
• a single controller, respectively electrically coupled to the N storage devices, for receiving data transmitted from the application I/O request unit, executing a predetermined operation for the received data to generate data to be written, transmitting the data to be written to the write caches of the N storage devices, duplicating the data to be written into the single backup memory, and labeling the duplicated data in the single backup memory as being valid in response to the writing confirm message, wherein when the storage space of the single backup memory is less than a threshold or when the addresses in the single backup memory where the data to be written are duplicated are overlapped, the controller issues a flush cache command to the N storage devices, and clears the data stored in the single backup memory in response to the flush cache finish message, wherein the single backup memory is only electrically connected to the single controller or one of the write caches in the controller, or is electrically connected between the single controller and the N storage devices, and wherein the predetermined operation is one selected from the group consisting of an XOR operation, a mirroring operation, a NO operation, a slice operation, a Galois field primitive polynomial operation, and a maximum distance separable code operation over finite fields.