Method and system for adaptive metadata replication

• US 20070118576A1
• Filed: 04/19/2006
• Published: 05/24/2007
• 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 8,495,010 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/184 implemented as replicated file system

Abstract

A method for writing a data block to a storage pool. The method including receiving a write operation for a block, determining whether the block comprises metadata, and if the block comprises metadata: determining a first replication type for the block, and writing the block to the storage pool in accordance with the first replication type. If the block does not comprise metadata: determining a second replication type for the block and writing the block to the storage pool in accordance with the second replication type.

Claims

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

receiving a write operation for a block;

determining whether the block comprises metadata; and

if the block comprises metadata;

determining a first replication type for the block;

writing the block to the storage pool in accordance with the first replication type;

if the block does not comprise metadata;

determining a second replication type for the block; and

writing the block to the storage pool in accordance with the second replication type.

2. The method of claim 1, wherein determining whether the block comprises metadata includes determining whether the block is one selected from the group consisting of a root block of the storage pool, a block associated with a global file system metadata, a block associated with a file system in the storage pool, and an indirect block associated with a file.

3. The method of claim 1, wherein determining a first replication type for the block comprises:

determining a class of metadata to which the block belongs;

determining whether the class of metadata is associated with a class-specific replication policy;

using the class-specific replication policy to determine the first replication type, if the class of metadata is associated with the class-specific replication policy; and

using a default metadata replication policy, if the class of metadata is not associated with the class-specific replication policy.

4. The method of claim 3, wherein the class of metadata corresponds to one selected from the group consisting of a root block class, a global file system metadata class, a file system metadata class, and an indirect block class.

5. The method of claim 1, wherein the block is associated with a file.

6. The method of claim 5, wherein the file is organized as a hierarchy of blocks and the block is part of the hierarchy of blocks.

7. A system, comprising:

a storage pool;

a file system configured to write a block to the storage pool using the following steps;

receiving a write operation for a block;

determining whether the block comprises metadata; and

if the block comprises metadata;

determining a first replication type for the block;

writing the block to the storage pool in accordance with the first replication type;

if the block does not comprise metadata;

determining a second replication type for the block; and

writing the block to the storage pool in accordance with the second replication type.

8. The system of claim 7, wherein determining whether the block comprises metadata includes determining whether the block is one selected from the group consisting of a root block of the storage pool, a block associated with a global file system metadata, a block associated with a file system in the storage pool, and an indirect block associated with a file.

9. The system of claim 7, wherein determining a first replication type for the block comprises:

determining a class of metadata to which the block belongs;

determining whether the class of metadata is associated with a class-specific replication policy;

using the class-specific replication policy to determine the first replication type, if the class of metadata is associated with the class-specific replication policy; and

using a default metadata replication policy, if the class of metadata is not associated with the class-specific replication policy.

10. The system of claim 9, wherein the class of metadata corresponds to one selected from the group consisting of a root block class, a global file system metadata class, a file system metadata class, and an indirect block class.

11. The system of claim 7, wherein the block is associated with a file in the file system.

12. The system of claim 11, wherein the file is organized as a hierarchy of blocks and the block is part of the hierarchy of blocks of the file system.

13. A system, 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

a metadata block, wherein the metadata block references at least one of the plurality of child blocks;

a parent block referencing at least one metadata block; and

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

wherein each metadata block corresponds to one of a plurality of classes of metadata,

wherein each metadata block is stored using a replication type corresponding to the one of the plurality of classes of metadata.

14. The system of claim 13, wherein the metadata block is one selected from the group consisting of a root block of the storage pool, a block associated with a global file system metadata, a block associated with a file system in the storage pool, and an indirect block associated with a file.

15. The system of claim 13, wherein each of the classes of metadata in the plurality of classes of metadata corresponds to one selected from the group consisting of a root block class, a global file system metadata class, a file system metadata class, and an indirect block class.

16. The system of claim 13, wherein the metadata block is associated with a file in a file system.

17. The method of claim 16, wherein the file is organized as a hierarchy of blocks and the block is part of the hierarchy of blocks in a file system.