ELASTIC CACHE OF REDUNDANT CACHE DATA

• US 20130198448A1
• Filed: 01/31/2012
• Published: 08/01/2013
• Est. Priority Date: 01/31/2012
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Ish, Mark, Baderdinni, Anant, Smerdon, Gary J.
• Granted Patent: US 8,966,170 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• CPC Class Codes: G06F 11/1666 where the redundant component is memory or memory area
• CPC Class Codes: G06F 11/20 using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/222 Non-volatile memory
• CPC Class Codes: G06F 2212/285 Redundant cache memory

Abstract

An apparatus for elastic caching of redundant cache data. The apparatus may have a plurality of buffers and a circuit. The circuit may be configured to (i) receive a write request from a host to store write data in a storage volume, (ii) allocate a number of extents in the buffers based upon a redundant organization associated with the write request and (iii) store the write data in the number of extents, where (a) each of the number of extents is located in a different one of the buffers and (b) the number of extents are dynamically linked together in response to the write request.

Claims

1. An apparatus for elastic caching of redundant cache data, comprising:

a plurality of buffers; and

a circuit configured to (i) receive a write request from a host to store write data in a storage volume, (ii) allocate a number of extents in said buffers based upon a redundant organization associated with said write request, and (iii) store said write data in said number of extents, wherein (a) each of said number of extents is located in a different one of said buffers and (b) said number of extents are dynamically linked together in response to said write request.

2. The apparatus according to claim 1, wherein said circuit is further configured to unlink at least one of said number of extents in response to copying said write data from said buffers to said storage volume.

3. The apparatus according to claim 1, wherein said number of extents are dynamically linked by changing a respective parameter corresponding to each of said number of extents.

4. The apparatus according to claim 3, wherein each of said respective parameters is changed to point to another extent in said number of extents.

5. The apparatus according to claim 1, wherein said circuit is further configured to allocate one or more extents based upon a non-redundant organization associated with another request received from said host.

6. The apparatus according to claim 1, wherein (i) said circuit is further configured to allocate another number of extents based upon another redundant organization associated with another write request received from said host and (ii) said another redundant organization is different than said redundant organization.

7. The apparatus according to claim 1, wherein said redundant organization comprises an organization used with a redundance array of independent disks.

8. The apparatus according to claim 1, wherein said apparatus is implemented as one or more integrated circuits.

9. A method for elastic caching of redundant cache data, comprising the steps of:

(A) receiving a write request from a host to an apparatus to store write data in a storage volume;

(B) allocating a number of extents in a plurality of buffers based upon a redundant organization associated with said write request; and

(C) storing said write data in said number of extents, wherein (i) each of said number of extents is located in a different one of said buffers and (ii) said number of extents are dynamically linked together in response to said write request.

10. The method according to claim 9, further comprising the step of:

unlinking at least one of said number of extents in response to copying said write data from said buffers to said storage volume.

11. The method according to claim 9, wherein said number of extents are dynamically linked by changing a respective parameter corresponding to each of said number of extents.

12. The method according to claim 11, wherein each of said respective parameters is changed to point to another extent in said number of extents.

13. The method according to claim 9, further comprising the step of:

allocating one or more extents based upon a non-redundant organization associated with another request received from said host.

14. The method according to claim 9, further comprising the steps of:

allocating another number of extents based upon another redundant organization associated with another write request received from said host, wherein said another redundant organization is different than said redundant organization.

15. The method according to claim 9, wherein said redundant organization comprises an organization used with a redundance array of independent disks.