Memory backup used in a raid system

• US 8,074,112 B1
• Filed: 12/05/2008
• Issued: 12/06/2011
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Chang, Lihan, Chu, Chee Hoe, Zhou, Wei, Lin, Chi-Chih
• Primary Examiner(s): Ehne, Charles
• Application Number:
  US12/329,128
• Time in Patent Office: 1,096 Days
• Field of Search: 714/5, 714/14, 714/22, 714/5.1, 714/6.22, 713/340
• US Class Current: 714/14
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: G06F 11/2015 Redundant power supplies power supply failure G06F1/30

Abstract

Systems, apparatuses, and methods for memory backup in a redundant array of independent disks (RAID) system are described. The methods include detecting a failure in a main power supply that supplies power to a volatile memory that is coupled to a RAID controller, switching to a temporary power supply to supply power to the volatile memory in response to detecting the main power supply failure, and transferring data from the volatile memory to a non-volatile memory coupled to the RAID controller subsequent to switching to the temporary power supply.

Claims

1. An apparatus comprising:

a redundant array of independent disk (RAID) controller configured to control a plurality of storage devices constituting a RAID disk array;

a volatile memory coupled to the RAID controller, the volatile memory configured to store data accessible by the RAID controller;

a non-volatile memory coupled to the RAID controller;

a memory interface configured to interface between the volatile memory and the non-volatile memory;

a main power supply configured to supply power to the volatile memory and the RAID controller; and

a temporary power supply configured to, in response to a failure of the main power supply, supply power to the volatile memory and the RAID controller;

wherein the RAID controller is further configured to

detect the failure of the main power supply, and

in response to having detected the failure of the main power supply, transfer data from the volatile memory to the non-volatile memory; and

wherein the temporary power supply is further configured to cease supplying power to the volatile memory and the RAID controller subsequent to, and in response to, completion of the transfer of data from the volatile memory to the non-volatile memory,

wherein the data is transferred, in response to detecting the failure of the main power supply, from the volatile memory to the non-volatile memory through the memory interface, by bypassing the RAID controller.

2. The apparatus of claim 1, wherein the non-volatile memory is a flash memory.

3. The apparatus of claim 1, wherein the volatile memory is a random access memory.

4. The apparatus of claim 1, wherein the temporary power supply is an uninterrupted power supply (UPS) unit, a battery backup unit (BBU), or a supercap.

5. The apparatus of claim 1, wherein the temporary power supply is configured to not supply power to a RAID disk interface in response to the failure of the main power supply.

6. The apparatus of claim 1, wherein the RAID controller is a RAID-on-chip (ROC) controller.

7. A method comprising:

detecting a failure in a main power supply that supplies power to a volatile memory, wherein the volatile memory is coupled to a redundant array of independent disk (RAID) controller;

in response to detecting the failure of the main power supply, switching to a temporary power supply to supply power to the volatile memory

subsequent to switching to the temporary power supply, transferring data from the volatile memory to a non-volatile memory coupled to the RAID controller, wherein said transferring data from the volatile memory to the non-volatile memory is performed through a memory interface, by bypassing the RAID controller, wherein the memory interface is configured to act as an interface between the volatile memory and the non-volatile memory; and

switching off the temporary power supply subsequent to, and in response to, completion of the transfer of the data from the volatile memory to the non-volatile memory.

8. The method of claim 7, wherein transferring data from the volatile memory to the non-volatile memory further comprises:

transferring data from the volatile memory to the RAID controller; and

transferring data from the RAID controller to the non-volatile memory.

9. The method of claim 7, further comprising:

supplying power to the RAID controller with the temporary power supply in response to the failure of the main power supply.

10. The method of claim 7, wherein switching to the temporary power supply comprises:

switching to the temporary power supply substantially instantaneously such that the data stored in the volatile memory is not corrupted due to the failure of the main power supply.

11. The method of claim 7, wherein the temporary power supply includes an uninterrupted power supply (UPS) unit, a battery backup unit (BBU), or a supercap.

12. The method of claim 7, wherein the non-volatile memory is a flash memory.

13. The method of claim 7, wherein the volatile memory is a random access memory (RAM).

14. A system comprising:

a storage medium; and

a plurality of instructions tangibly stored on the storage medium;

wherein the plurality of instructions are configured to cause one or more processors to perform a plurality of memory backup operations, the plurality of memory backup operations comprising;

detecting a failure in a main power supply that supplies power to a volatile memory, wherein the volatile memory is coupled to a redundant array of independent disk (RAID) controller;

in response to detecting the failure of the main power supply, switching to a temporary power supply to supply power to the volatile memory

subsequent to switching to the temporary power supply, transferring data from the volatile memory to a non-volatile memory coupled to the RAID controller, wherein said transferring data from the volatile memory to the non-volatile memory is performed through a memory interface, by bypassing the RAID controller, wherein the memory interface is configured to act as an interface between the volatile memory and the non-volatile memory; and

switching off the temporary power supply subsequent to, and in response to, completion of the transfer of the data from the volatile memory to the non-volatile memory.

15. The system of claim 14, the plurality of memory backup operations further comprise:

in response to the failure of the main power supply, powering the RAID controller with the temporary power supply.