SIMPLIFIED COPY OFFLOAD

• US 20150234715A1
• Filed: 09/08/2014
• Published: 08/20/2015
• Est. Priority Date: 10/26/2012
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Knight, Frederick E., Meneghini, John, Rao, Santosh A., Rajendran, Aurn Kumar
• Granted Patent: US 9,280,425 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Methods and apparatuses for performing simplified copy offload operations are provided. In one exemplary embodiment, a method includes creating a persistent point-in-time image of a data set of a source storage device in response to receiving a token request for a copy offload operation from a host. Creating the persistent point-in-time image includes generating pointers to data blocks of the data set, but does not include duplicating the data blocks. The method also includes transmitting a token that is a representation of the persistent point-in-time image to the host in response to the request.

Claims

1. A method comprising:

in response to receiving a token request for a copy offload operation from a host, creating a persistent point-in-time image of a data set of a source storage device, wherein the creating includes generating pointers to data blocks of the data set and does not include duplicating the data blocks; and

transmitting a token that is a representation of the persistent point-in-time image to the host in response to the request.

2. The method of claim 1 further comprising writing to the data set without affecting the persistent point-in-time image and the token.

3. The method of claim 2 wherein writing to the data set includes storing new data associated with the writing in different physical locations of the source data storage device than are used for the data blocks and leaving the data blocks unchanged.

4. The method of claim 1 wherein the persistent point-in-time image is a single instance storage clone of the data set.

5. The method of claim 1 further comprising:

receiving, at the source storage device, a request to copy the dataset, the request including the token and an indication of a destination data storage device;

transferring the data set from the persistent point-in-time image to the destination data storage device, without transferring the data set to the host, if the source data storage device and the destination storage device are not the same device; and

generating a new instance of the persistent point-in-time image on the source data storage device if the source data storage device and the destination storage device are the same device.

6. The method of claim 1 further comprising:

receiving, at a destination storage device, a request to copy the dataset, the request including the token;

retrieving the data set from the persistent point-in-time image by the destination data storage device, without transferring the data set to the host, if the source data storage device and the destination storage device are not the same device; and

generating a new instance of the persistent point-in-time image if the source data storage device and the destination storage device are the same device.

7. The method of claim 1 wherein the copy offload operation is a Small Computer System Interface (SCSI) T10 compliant copy offload operation.

8. The method of claim 1 wherein the token is a first token, the persistent point-in-time image is a first point-in-time image, and further comprising:

creating, in the source data storage device, a second persistent point-in-time image that is associated with a second data set in response to a second token request that identifies the second data set; and

transmitting a second token that is a representation of the second persistent point-in-time image in response to the second token request.

9. The method of claim 1 wherein the token expires at a designated expiration time.

10. The method of claim 9 wherein storage space associated with the token and the persistent point-in-time image is freed when the token expires.

11. The method of claim 1 wherein the token and the persistent point-in-time image are stored in a reserved area in the data storage device.

12. The method of claim 1 wherein the token and the persistent point-in-time image are stored in separate reserved areas.

13. The method of claim 8 wherein the first token, the second token, the first persistent point-in-time image, and the second persistent point-in-time image are stored in a file in the source data storage device.

14. The method of claim 1 wherein a Network Attached Storage (NAS) device receives the token request and creates the persistent point-in-time image.

15. The method of claim 1 wherein a Storage Area Network (SAN) device receives the token request and creates the persistent point-in-time image.

16. A data storage system comprising:

a data storage device; and

a processor configured to;

create a persistent point-in-time image of a data set of a source storage device in response to receiving a token request associated with a copy offload operation from a host, wherein the persistent point-in-time image includes pointers to data blocks of the data set and does not include duplicates of the data blocks;

store the token and the persistent point-in-time image in a file; and

transmit a token that is a representation of the persistent point-in-time image to the host in response to the request.

17. The data storage system of claim 16 wherein the processor is further configured to change the data set without changing the persistent point-in-time image by writing changed data blocks to different physical locations of the data storage device and leaving the data blocks unchanged.

18. The data storage system of claim 16 wherein the processor is further configured to:

receive a request to copy the dataset, the request including the token;

validate the token;

transfer the data set from the persistent point-in-time image to a destination data storage device, without transferring the data set to the host, if the data storage device and the destination storage device are not a same device; and

create a new instance of the persistent point-in-time image on the data storage device if the data storage device and the destination storage device are the same device.

19. The data storage system of claim 16 wherein the token is a first token, the persistent point-in-time image is a first point-in-time image, and the processor is further configured to:

create a second persistent point-in-time image that is associated with a second data set in response to receiving a second token request identifying the second data set;

generate a second token that is a representation of the second persistent point-in-time image;

store the second token and the second persistent point-in-time image; and

transmit the second token in response to the second token request.

20. The data storage system of claim 16 wherein the token is SCSI compliant.

21. The data storage system of claim 16 wherein the token expires at a designated expiration time and storage space associated with the token and the persistent point-in-time image is freed when the token expires.

22. The data storage system of claim 16 wherein the token and the persistent point-in-time image are stored in a file.

23. The data storage system of claim 16 wherein the token and the persistent point-in-time image are stored in separate files in the data storage device.

24. The data storage system of claim 19 wherein the first token, the second token, the first persistent point-in-time image, and the second persistent point-in-time image are stored in a file in the data storage device.

25. A non-transitory machine-readable medium comprising instructions that, when executed by at least one processor, direct the at least one processor to perform a copy offload operation that includes:

generate a clone of a data set of a source storage device by creating a point-in-time image of the data set that includes pointers to data blocks of the data set and does not include duplicates of the data blocks, wherein the clone is generated in response to receiving a token request from a host for the copy offload operation that identifies the data set;

store, in at least one dedicated area, the clone and a token that is a representation of the clone;

transmit the token to the host in response to the token request;

in response to receiving the token and an indication of a destination storage device, transfer the data set from the cloned data blocks to the destination storage device without transferring the data set to the host if the data source storage device and the destination storage device are not the same device and create a new instance of the clone on the source storage device if the source storage device and the destination storage device are the same device.

26. The medium of claim 25 wherein the token is a first token, the clone is a first clone, and the processor is further configured to:

receive a second token request identifying a second data set of the source storage device to be copied;

create a second clone that is associated with the second data set;

generate a second token that is a representation of the second clone; and

transmit the second token to the host in response to the second token request.

27. The medium of claim 25 wherein the token request is a tokenized SCSI read message.

28. The medium of claim 25 wherein the token is received in a tokenized SCSI write message.

29. The medium of claim 26 wherein the at least one dedicated area is one dedicated area and the first token, the second token, the first clone, and the second clone are stored in the one dedicated area.

30. The medium of claim 25 wherein the token and the clone are stored in separate dedicated areas.