Method and system for block reallocation

• US 20070106870A1
• Filed: 04/19/2006
• Published: 05/10/2007
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Ahrens, Matthew, Moore, William, Bonwick, Jeffrey
• Granted Patent: US 7,877,554 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 12/0238 Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory

Abstract

A system includes a storage pool including a first disk and a second disk, a data management unit (DMU), and a storage pool allocator (SPA). The SPA is configured to receive a request from the DMU to write a logical block, allocate a first physical block on the first disk, attempt to write the logical block to the first physical block, and allocate a second physical block on the second disk, if the attempt to write the logical block to the first physical block fails.

Claims

1. A system comprising:

a storage pool comprising a first disk and a second disk;

a data management unit (DMU); and

a storage pool allocator (SPA) configured to;

receive a first request from the DMU to write a logical block;

allocate a first physical block on the first disk;

attempt to write the logical block to the first physical block; and

allocate a second physical block on the second disk, if the attempt to write the logical block to the first physical block fails.

2. The system of claim 1, wherein the SPA is further configured to:

send a location of the first physical block to the DMU, after the first logical block has been written to the first physical block.

3. The system of claim 2, wherein the DMU is configured to:

place the location of the first physical block in a block pointer of an indirect block; and

send a second request to the SPA to write the indirect block.

4. The system of claim 1, wherein the SPA is further configured to:

attempt to write the logical block to the second physical block.

5. The system of claim 1, wherein the first physical block is allocated using a metadata-based allocation policy.

6. The system of claim 1, wherein the first physical block is allocated using a latency-based allocation policy.

7. The system of claim 1, wherein the logical block is an indirect block comprising a block pointer referencing a data block.

8. A method for writing a logical block in a storage pool, comprising:

receiving, by a storage pool allocator (SPA), a first request from a data management unit (DMU) to write the logical block;

allocating, by the SPA, a first physical block on a first disk in the storage pool;

attempting to write the logical block to the first physical block; and

allocating, by the SPA, a second physical block on a second disk in the storage pool, if attempting to write the logical block to the first physical block fails.

9. The method of claim 8, further comprising:

attempting to write the logical block to the second physical block.

10. The method of claim 8, further comprising:

sending a location of the first physical block to the DMU, after the first logical block has been written to the first physical block.

11. The method of claim 10, further comprising:

placing, by the DMU, the location of the first physical block in a block pointer of an indirect block; and

sending a second request to the SPA to write the indirect block.

12. The method of claim 8, wherein the first physical block is allocated using a metadata-based allocation policy.

13. The method of claim 8, wherein the first physical block is allocated using a latency-based allocation policy.

14. The method of claim 8, wherein the logical block is an indirect block comprising a block pointer referencing a data block.

15. A computer readable medium comprising executable instructions for writing a logical block in a storage pool by:

receiving, by a storage pool allocator (SPA), a first request from a data management unit (DMU) to write the logical block;

allocating, by the SPA, a first physical block on a first disk in the storage pool;

attempting to write the logical block to the first physical block; and

allocating, by the SPA, a second physical block on a second disk in the storage pool, if attempting to write the logical block to the first physical block fails.

16. The computer readable medium of claim 15, further comprising executable instructions for writing a logical block in a storage pool by:

attempting to write the logical block to the second physical block.

17. The computer readable medium of claim 15, further comprising executable instructions for writing a logical block in a storage pool by:

sending a location of the first physical block to the DMU, after the first logical block has been written to the first physical block.

18. The computer readable medium of claim 17, further comprising executable instructions for writing a logical block in a storage pool by:

placing, by the DMU, the location of the first physical block in a block pointer of an indirect block; and

sending a second request to the SPA to write the indirect block.

19. The computer readable medium of claim 15, wherein the first physical block is allocated using at least one selected from the group consisting of a metadata-based allocation policy and a latency-based allocation policy.

20. The computer readable medium of claim 15, wherein the logical block is an indirect block comprising a block pointer referencing a data block.