Multiple replication levels with pooled devices

• US 7,865,673 B2
• Filed: 04/19/2006
• Issued: 01/04/2011
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Oracle America, Inc. (Oracle Corporation)
• Inventors: Bonwick, Jeffrey S., Moore, William H.
• Primary Examiner(s): Thomas; Shane M
• Assistant Examiner(s): Chrzanowski; Matthew R
• Application Number:
  US11/406,956
• Publication Number:
  US 20070106864A1
• Time in Patent Office: 1,721 Days
• Field of Search: None
• US Class Current: 711/154
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/2056 by mirroring
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: G06F 2211/105 On the fly coding, e.g. using XOR accumulators
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method for writing data to a storage pool, including receiving a first write operation for a first block, determining a first replication type for the first block, determining a number of physical blocks (n1) required to write the first block to the storage pool using a size of the first block and the first replication type, if n1 is not a multiple of the maximum supported replication level of the storage pool: allocating a number of padded physical blocks (p1) to n1 until n1+p1 is a multiple of a maximum supported replication level of the storage pool, and writing the first block to the storage pool by filling in the n1 physical blocks.

Claims

1. A method for writing data to a storage pool, comprising:

receiving a first write operation for a first block;

determining a first replication type for the first block;

determining a number of physical blocks (n1) required to write the first block to the storage pool using a size of the first block and the first replication type;

if n1 is not a multiple of a maximum supported replication level of the storage pool;

allocating a number of padded physical blocks (p1) to n1 until n1+p1 is a multiple of the maximum supported replication level of the storage pool, and

writing the first block to the storage pool by filling in the n1 physical blocks; and

if n1 is a multiple of the maximum supported replication level of the storage pool, writing the first block to the storage pool by filling in n1 physical blocks.

2. The method of claim 1, further comprising:

receiving a second write operation for a second block;

determining a second replication type for the second block;

determining a number of physical blocks (n2) required to write the second block to the storage pool using a size of the second block and the second replication type;

if n2 is not a multiple of the maximum supported replication level of the storage pool;

allocating a number of padded physical blocks (p2) to n2 until n2+p2 is a multiple of the maximum supported replication level of the storage pool, and

writing the second block to the storage pool by filling in n2 physical blocks; and

if n2 is a multiple of the maximum supported replication level of the storage pool, writing the second block to the storage pool by filling in n2 physical blocks.

3. The method of claim 2, wherein the first block is a data block and the second block is an indirect block comprising a block pointer referencing the first block.

4. The method of claim 3, wherein the first replication type is stored in the second block, and wherein the second replication type is stored in a parent block comprising a block pointer referencing the second block.

5. The method of claim 2, wherein the first replication type is stored in a first parent block comprising a block pointer referencing the first block, and wherein the second replication type is stored in a second parent block comprising a block pointer referencing the second block.

6. The method of claim 2, wherein the first block and the second block correspond to a portion of a hierarchical tree structure representing a file in a file system.

7. The method of claim 1, wherein writing the first block to the storage pool by filling in n1 physical blocks, comprises:

determining a number of rows (r) required to store the first block in the storage pool using n1;

dividing the first block into a plurality of sequential blocks (s), wherein each of the plurality of blocks is the same size as a physical block;

writing a first r sequential blocks to a first disk in the storage pool; and

writing a r+1^th sequential block to a second disk in the storage pool,

wherein s>

r.

8. The method of claim 7, wherein r is calculated using the following formula:

r=((n1−

1) div d) +1, where d is the number of disks in the storage pool.

9. A system for writing data, comprising:

a storage pool comprising;

a plurality of child blocks, wherein each of the plurality of child blocks comprises one selected from the group consisting of a data block and an indirect block, wherein the indirect block references at least one of the plurality of child blocks;

a parent block referencing at least one indirect block; and

a storage pool allocator configured to store the root block and the plurality of child blocks,

a file system operatively connected to the storage pool, wherein the file system is configured to store a first block in the storage pool using the following method;

determining a first replication type for a first block;

determining a number of physical blocks (n1) required to write the block to the storage pool using a size of the first block and the first replication type;

if n1 is not a multiple of a maximum supported replication level of the storage pool;

allocating a number of padded physical blocks (p1) to n1 until n1+p1 is a multiple of the maximum supported replication level of the storage pool, and

writing the first block to the storage pool by filling in n1 physical blocks; and

if n1 is a multiple of the maximum supported replication level of the storage pool, writing the first block to the storage pool by filling in n1 physical blocks,

wherein the first block is one selected from the group consisting of the child block and the parent block.

10. The system of claim 9, wherein the file system if further configured to store a second block in the storage pool using the following method:

receiving a second write operation for a second block;

determining a second replication type for the second block;

determining a number of physical blocks (n2) required to write the second block to the storage pool using a size of the second block and the second replication type;

if n2 is not a multiple of the maximum supported replication level of the storage pool;

allocating a number of padded physical blocks (p2) to n2 until n2+p2 is a multiple of the maximum supported replication level of the storage pool, and

writing the second block to the storage pool by filling in n2 physical blocks; and

if n2 is a multiple of the maximum supported replication level of the storage pool, writing the second block to the storage pool by filling in n2 physical blocks,

wherein the first block is one selected from the group consisting of the child block and the parent block.

11. The system of claim 10, wherein the first block and the second block correspond to a portion of a hierarchical tree structure representing a file.

12. The system of claim 10, wherein the second replication type is stored in the first block.

13. The system method of claim 9, wherein writing the first block to the storage pool by filling in n1 physical blocks, comprises:

determining a number of rows (r) required to store the first block in the storage pool using n1;

dividing the first block into a plurality of sequential blocks (s), wherein each of the plurality of blocks is the same size as a physical block;

writing a first r sequential blocks to a first disk in the storage pool; and

writing a r+1^th sequential block to a second disk in the storage pool,

wherein s>

r.

14. The system of claim 13, wherein r is calculated using the following formula:

r=((n1−

1) div d) +1, where d is the number of disks in the storage pool.

15. A non-transitory computer readable medium comprising computer readable program code embodied therein for causing a computer system to:

receiving a first write operation for a first block;

determining a first replication type for the first block;

determining a number of physical blocks (n1) required to write the first block to the storage pool using a size of the first block and the first replication type;

if n1 is not a multiple of a maximum supported replication level of the storage pool;

allocating a number of padded physical blocks (p1) to n1 until n1+p1 is a multiple of the maximum supported replication level of the storage pool, and

writing the first block to the storage pool by filling in n1 physical blocks; and

if n1 is a multiple of the maximum supported replication level of the storage pool, writing the first block to the storage pool by filling in n1 physical blocks.

16. The non-transitory computer readable medium of claim 15, further comprising:

receiving a second write operation for a second block;

determining a second replication type for the second block;

determining a number of physical blocks (n2) required to write the second block to the storage pool using a size of the second block and the second replication type;

if n2 is not a multiple of the maximum supported replication level of the storage pool;

allocating a number of padded physical blocks (p2) to n2 until n2+p2 is a multiple of the maximum supported replication level of the storage pool, and

writing the second block to the storage pool by filling in n2 physical blocks; and

if n2 is a multiple of the maximum supported replication level of the storage pool, writing the second block to the storage pool by filling in n2 physical blocks.

17. The non-transitory computer readable medium of claim 16, wherein the first block is a data block and the second block is an indirect block comprising a block pointer referencing the first block.

18. The non-transitory computer readable medium of claim 16, wherein the first block and the second block correspond to a portion of a hierarchical tree structure representing a file in a file system.

19. The non-transitory computer readable medium of claim 15, wherein writing the first block to the storage pool by filling in n1 physical blocks, comprises:

determining a number of rows (r) required to store the first block in the storage pool using n1;

dividing the first block into a plurality of sequential blocks (s), wherein each of the plurality of blocks is the same size as a physical block;

writing a first r sequential blocks to a first disk in the storage pool; and

writing a r+1^th sequential block to a second disk in the storage pool,

wherein s>

r.

20. The non-transitory computer readable medium of claim 19, wherein r is calculated using the following formula:

r=((n1−

1) div d) +1, where d is the number of disks in the storage pool.