Managing a Storage Cache Utilizing Externally Assigned Cache Priority Tags

• US 20120117328A1
• Filed: 11/04/2010
• Published: 05/10/2012
• Est. Priority Date: 11/04/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: McKean, Brian, Ish, Mark
• Granted Patent: US 8,595,451 B2
• Time in Patent Office: Days
• US Class Current: 711/136
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/126 with special data handling, e.g. priority of data or instructions, handling errors or pinning
• CPC Class Codes: G06F 2212/261 Storage comprising a plurality of storage devices

Abstract

A method for caching data in a storage medium implementing tiered data structures may include storing a first portion of critical data at the instruction of a storage control module. The first portion of critical data may be separated into data having different priority levels based upon at least one data utilization characteristic associated with a file system implemented by the storage control module. The method may also include storing a second portion of data at the instruction of the storage control module. The second storage medium may have at least one performance, reliability, or security characteristic different from the first storage medium.

Claims

1. A device, comprising:

a storage control module for storing a first portion of critical data and a second portion of data at the instruction of an operating system;

a first storage medium coupled with the storage control module for storing the first portion of critical data, where the first portion of critical data is separated into data having different priority levels based upon at least one data utilization characteristic associated with a file system implemented by the storage control module; and

a second storage medium coupled with the storage control module for storing the second portion of data, where the second storage medium has at least one performance, reliability, or security characteristic different from the first storage medium.

2. The device of claim 1, wherein the first storage medium is logically configured to provide a plurality of Least Recently Used (LRU) data structures.

3. The device of claim 2, wherein the LRU data structures are configured to optimally place data in the first storage medium and the second storage medium according to the relative performance, reliability, or security characteristics of the first storage medium and the second storage medium, such that the first storage medium is first populated with data referenced by the highest priority LRU data structures.

4. The device of claim 2, wherein a least recently used data block in a first LRU data structure is demoted to a second LRU data structure having a lower priority than the first LRU data structure.

5. The device of claim 1, wherein the first storage medium is logically configured to provide an insertion threshold set below the lowest utilized priority level in the first storage medium.

6. The device of claim 1, wherein a data block associated with a cache hit in a first data structure is promoted to a second data structure having a higher priority than the first data structure when a priority associated with the cache hit is greater than the priority of the first data structure.

7. The device of claim 1, wherein the data utilization characteristic associated with a file system implemented by the storage control module includes at least one of a designation of metadata associated with the file system or the actual contents of a file.

8. The device of claim 1, wherein a higher priority cache block is moved to a lower priority data structure when the cache block is not referenced for some period of time.

9. A method, comprising:

storing a first portion of critical data at the instruction of an storage control module, where the first portion of critical data is separated into data having different priority levels based upon at least one data utilization characteristic associated with a file system implemented by the storage control module; and

storing a second portion of data at the instruction of the storage control module, where the second storage medium has at least one performance, reliability, or security characteristic different from the first storage medium.

10. The method of claim 9, further comprising:

logically configuring the first storage medium to provide a plurality of Least Recently Used (LRU) data structures.

11. The method of claim 10, further comprising:

demoting a least recently used data block in a first LRU data structure to a second LRU data structure having a lower priority than the first LRU data structure.

12. The method of claim 9, further comprising:

logically configuring the first storage medium to provide an insertion threshold set below the lowest utilized priority level in the first storage medium.

13. The method of claim 9, further comprising:

promoting a data block associated with a cache hit in a first data structure to a second data structure having a higher priority than the first data structure when a priority associated with the cache hit is greater than the priority of the first data structure.

14. The method of claim 9, wherein the data utilization characteristic associated with a file system implemented by the storage control module includes at least one of a designation of metadata associated with the file system or the actual contents of a file.

15. The method of claim 9, further comprising:

moving a higher priority cache block to a lower priority data structure when the cache block is not referenced for some period of time.

16. A system, comprising:

a storage network for coupling with the application server, the storage network including

a storage control module for storing a first portion of critical data and a second portion of data at the instruction of an operating system;

a first storage medium coupled with the storage control module for storing the first portion of critical data, where the first portion of critical data is separated into data having different priority levels based upon at least one data utilization characteristic associated with a file system implemented by the storage control module; and

a second storage medium coupled with the storage control module for storing the second portion of data, where the second storage medium has at least one performance, reliability, or security characteristic different from the first storage medium.

17. The system of claim 16, wherein the first storage medium is logically configured to provide a plurality of Least Recently Used (LRU) data structures.

18. The system of claim 17, wherein a least recently used data block in a first LRU data structure is demoted to a second LRU data structure having a lower priority than the first LRU data structure.

19. The system of claim 16, wherein the first storage medium is logically configured to provide an insertion threshold set below the lowest utilized priority level in the first storage medium.

20. The system of claim 16, wherein a data block associated with a cache hit in a first data structure is promoted to a second data structure having a higher priority than the first data structure when a priority associated with the cache hit is greater than the priority of the first data structure.

21. The system of claim 16, wherein the data utilization characteristic associated with a file system implemented by the storage control module includes at least one of a designation of metadata associated with the file system or the actual contents of a file.