Systems and methods for performing copy-on-write operations

Patent metadata

Field	Value
Publication number	US-9405709-B1
Application number	US-201213672626-A
Country	US
Kind code	B1
Filing date	Nov 8, 2012
Priority date	Aug 13, 2012
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A computer-implemented method for performing copy-on-write operations may include (1) identifying a write operation addressed to at least a part of a storage area on a storage system, (2) determining that the storage area is configured to be copied before writing to the storage area in order to preserve original data stored within the storage area, (3) identifying an interface for offloading copy-on-write operations to the storage system, and (4) using the interface to instruct the storage system to create a copy of the storage area modified with the write operation. Various other methods, systems, and computer-readable media are also disclosed.

First claim

What is claimed is:

1. A computer-implemented method for performing copy-on-write operations, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising:
identifying a write operation addressed to at least a part of a storage area on a storage system, the write operation comprising a block-level write operation;
determining that the storage area falls within a snapshot and that, therefore, the entire storage area is configured to be copied as a chunk before writing to the storage area in order to preserve original data stored within the storage area, wherein a chunk size encompassing the entire storage area is larger than a size of the block-level write operation;
identifying an interface for offloading copy-on-write operations to the storage system;
using the interface, in response to identifying the block-level write operation, to instruct the storage system to create a copy of the storage area before the storage area is modified with the write operation.

2. The computer-implemented method of claim 1 , wherein using the interface comprises:
specifying to the storage system an offset of the write operation within the storage area;
passing a buffer comprising a content of the write operation to the storage system.

3. The computer-implemented method of claim 1 , wherein using the interface comprises:
specifying to the storage system a location of the storage area;
specifying to the storage system a target location at which to create the copy of the storage area modified with the write operation;
specifying to the storage area a size of the storage area;
specifying to the storage system an offset of the write operation within the storage area;
passing a buffer comprising a content of the write operation to the storage system.

4. The computer-implemented method of claim 1 , wherein the interface comprises an interface between the storage system and a mapping layer that maps logical data locations to physical data locations on the storage system.

5. The computer-implemented method of claim 4 , wherein using the interface comprises instructing the storage system to create the copy of the storage area modified with the write operation without passing data within the storage area from the storage system to the mapping layer.

6. The computer-implemented method of claim 1 , wherein the interface comprises an interface between the storage system and at least one of:
a file system;
a database.

7. The computer-implemented method of claim 1 , wherein determining that the storage area is configured to be copied before writing to the storage area in order to preserve original data stored within the storage area comprises determining that the storage area comprises deduplicated data.

8. A system for performing copy-on-write operations, the system comprising:
an identification module programmed to identify a write operation addressed to at least a part of a storage area on a storage system, the write operation comprising a block-level write operation;
a determination module programmed to determine that the storage area falls within a snapshot and that, therefore, the entire storage area is configured to be copied as a chunk before writing to the storage area in order to preserve original data stored within the storage area, wherein a chunk size encompassing the entire storage area is larger than a size of the block-level write operation;
an interface module programmed to identify an interface for offloading copy-on-write operations to the storage system;
an instruction module programmed to use the interface, in response to identifying the block-level write operation, to instruct the storage system to create a copy of the storage area before the storage area is modified with the write operation;
at least one processor configured to execute the identification module, the determination module, the interface module, and the instruction module.

9. The system of claim 8 , wherein the instruction module is programmed to use the interface by:
specifying to the storage system an offset of the write operation within the storage area;
passing a buffer comprising a content of the write operation to the storage system.

10. The system of claim 8 , wherein the instruction module is programmed to use the interface by:
specifying to the storage system a location of the storage area;
specifying to the storage system a target location at which to create the copy of the storage area modified with the write operation;
specifying to the storage area a size of the storage area;
specifying to the storage system an offset of the write operation within the storage area;
passing a buffer comprising a content of the write operation to the storage system.

11. The system of claim 8 , wherein the interface comprises an interface between the storage system and a mapping layer that maps logical data locations to physical data locations on the storage system.

12. The system of claim 11 , wherein using the interface comprises instructing the storage system to create the copy of the storage area modified with the write operation without passing data within the storage area from the storage system to the mapping layer.

13. The system of claim 8 , wherein the interface comprises an interface between the storage system and at least one of:
a file system;
a database.

14. The system of claim 8 , wherein the determination module is programmed to determine that the storage area is configured to be copied before writing to the storage area in order to preserve original data stored within the storage area by determining that the storage area comprises deduplicated data.

15. A non-transitory computer-readable medium comprising one or more computer-executable instructions that, when executed by at least one processor of a computing device, cause the computing device to:
identify a write operation addressed to at least a part of a storage area on a storage system, the write operation comprising a block-level write operation;
determine that the storage area falls within a snapshot and that, therefore, the entire storage area is configured to be copied as a chunk before writing to the storage area in order to preserve original data stored within the storage area, wherein a chunk size encompassing the entire storage area is larger than a size of the block-level write operation;
identify an interface for offloading copy-on-write operations to the storage system;
use the interface, in response to identifying the block-level write operation, to instruct the storage system to create a copy of the storage area before the storage area is modified with the write operation.

16. The non-transitory computer-readable medium of claim 15 , wherein the one or more computer-executable instructions cause the computing device to use the interface by causing the computing device to:
specify to the storage system an offset of the write operation within the storage area;
pass a buffer comprising a content of the write operation to the storage system.

17. The non-transitory computer-readable medium of claim 15 , wherein using the interface comprises:
specifying to the storage system a location of the storage area;
specifying to the storage system a target location at which to create the copy of the storage area modified with the write operation;
specifying to the storage area a size of the storage area;
specifying to the storage system an offset of the write operation within the storage area;
passing a buffer comprising a content of the write

Assignees

• Symantec Corp
• Veritas Technologies Llc

Inventors

• Salpekar Ajay
• Kumaresan Balemurughan
• Joshi Darshan

Classifications

• G06F3/0614 Primary

  Improving the reliability of storage systems · CPC title

• G06F11/16

  Error detection or correction of the data by redundancy in hardware · CPC title

• G06F11/00

  Error detection; Error correction; Monitoring (error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00) · CPC title

• G06F12/16 Primary

  Protection against loss of memory contents {(contains no material, see G06F11/00)} · CPC title

• G06F3/065

  Replication mechanisms · CPC title