Check-pointing of metadata

• US 9,875,055 B1
• Filed: 08/04/2014
• Issued: 01/23/2018
• Est. Priority Date: 08/04/2014
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Neppalli, Srinivas, Yu, Raymond
• Primary Examiner(s): Lo, Ann J
• Assistant Examiner(s): Villanueva, Leandro
• Application Number:
  US14/451,115
• Time in Patent Office: 1,268 Days
• Field of Search: None
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0674 Disk device
• CPC Class Codes: G06F 3/068 Hybrid storage device

Abstract

Managing data stored in a Data Storage Device (DSD) including a volatile memory and a non-volatile memory including a circular buffer. Metadata stored in the volatile memory is logically divided into blocks of metadata. At least one changed block of metadata is identified that has changed during operation of the DSD and the at least one changed block of metadata is stored in the circular buffer of the non-volatile memory.

Claims

1. A Data Storage Device (DSD), comprising:

a volatile memory for storing metadata;

a non-volatile memory including a disk; and

a controller configured to;

logically divide the metadata into blocks of metadata;

identify at least one changed block of metadata that has changed during operation of the DSD; and

store the at least one changed block of metadata in a circular buffer in overlapping tracks on the disk.

2. The DSD of claim 1, wherein the metadata includes a translation table associating logical block addresses for data stored in the DSD with physical block addresses identifying locations where the data is stored in the DSD.

3. The DSD of claim 1, wherein the controller is further configured to:

receive write commands from a host to store data in the DSD; and

store the at least one changed block of metadata in the circular buffer after receiving a predetermined number of write commands from the host.

4. The DSD of claim 1, wherein the controller is further configured to:

receive write commands from a host to store data in the DSD; and

store the at least one changed block of metadata in the circular buffer after a predetermined amount of time of not receiving any write commands from the host.

5. The DSD of claim 1, wherein the non-volatile memory includes a solid-state memory.

6. The DSD of claim 1, wherein the non-volatile memory further includes a root area for storing mapping data indicating a location of at least a portion of the metadata stored in the circular buffer.

7. The DSD of claim 6, wherein the controller is further configured to update the mapping data in the root area based on storing the at least one changed block of metadata in the circular buffer.

8. The DSD of claim 1, wherein the controller is further configured to ensure coherency between the at least one changed block of metadata stored in the volatile memory and the at least one changed block of metadata being stored in the circular buffer when storing the at least one changed block of metadata in the circular buffer.

9. The DSD of claim 8, wherein the controller is further configured to block further changes to the at least one changed block of metadata stored in the volatile memory when storing the at least one changed block of metadata in the circular buffer to ensure coherency between the at least one changed block of metadata stored in the volatile memory and the at least one changed block of metadata being stored in the circular buffer.

10. The DSD of claim 1, wherein the controller is further configured to identify the at least one changed block of metadata using at least one flag indicating a change to metadata corresponding to the at least one changed block of metadata.

11. A method for managing data stored in a Data Storage Device (DSD) comprising a volatile memory and a non-volatile memory including a disk, the method comprising:

logically dividing metadata stored in the volatile memory into blocks of metadata;

identifying at least one changed block of metadata that has changed during operation of the DSD; and

storing the at least one changed block of metadata in a circular buffer in overlapping tracks on the disk.

12. The method of claim 11, wherein the metadata includes a translation table associating logical block addresses for data stored in the DSD with physical block addresses identifying locations where the data is stored in the DSD.

13. The method of claim 11, further comprising:

receiving write commands from a host to store data in the DSD; and

storing the at least one changed block of metadata in the circular buffer after receiving a predetermined number of write commands from the host.

14. The method of claim 11, further comprising:

receiving write commands from a host to store data in the DSD; and

storing the at least one changed block of metadata in the circular buffer after a predetermined amount of time of not receiving any write commands from the host.

15. The method of claim 11, wherein the non-volatile memory includes a solid-state memory.

16. The method of claim 11, wherein the non-volatile memory further includes a root area for storing mapping data indicating a location of at least a portion of the metadata stored in the circular buffer.

17. The method of claim 16, further comprising updating the mapping data in the root area based on storing the at least one changed block of metadata in the circular buffer.

18. The method of claim 11, further comprising ensuring coherency between the at least one changed block of metadata stored in the volatile memory and the at least one changed block of metadata being stored in the circular buffer when storing the at least one changed block of metadata in the circular buffer.

19. The method of claim 18, further comprising blocking further changes to the at least one changed block of metadata stored in the volatile memory when storing the at least one changed block of metadata in the circular buffer to ensure coherency between the at least one changed block of metadata stored in the volatile memory and the at least one changed block of metadata being stored in the circular buffer.

20. The method of claim 11, further comprising identifying the at least one changed block of metadata using at least one flag indicating a change to metadata corresponding to the at least one changed block of metadata.

21. A computer readable storage medium storing computer-executable instructions for managing data stored in a Data Storage Device (DSD) comprising a volatile memory and a non-volatile memory including a disk, wherein when the computer-executable instructions are executed by a processor or controller, the computer-executable instructions cause the processor or controller to:

logically divide metadata stored in the volatile memory into blocks of metadata;

identify at least one changed block of metadata that has changed during operation of the DSD; and

store the at least one changed block of metadata in a circular buffer in overlapping tracks on the disk.