Selection of a data path based on operation type

• US 7,962,657 B1
• Filed: 12/28/2007
• Issued: 06/14/2011
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Zimran, Eyal, Faibish, Sorin, Glasgow, Jason
• Primary Examiner(s): Dalencourt; Yves
• Application Number:
  US11/966,615
• Time in Patent Office: 1,264 Days
• Field of Search: 709/250, 709/217, 709/218
• US Class Current: 709/250
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

Embodiments of the present invention are directed to techniques for selecting a data path over which to exchange information between a client device and a storage system by making a selection between a file system server (NAS) data path type (a first data path type) and a direct (SAN) data path type (a second data path type) based on one or more adjustable path selection factors and/or information regarding components of the computer system. For example, a data path may be selected based on a type of an input/output operation to be executed (i.e., whether the operation is a read operation or write operation) and/or any other suitable path selection factor.

Claims

1. A method for use in a computer system, the method comprising:

determining whether an input/output (I/O) operation seeks to write at least some of a first set of information to at least one storage system, the computer system comprising at least one client device, the at least one storage system that provides at least one volume of storage to store information and at least one file system server that provides a file system interface for at least some of the information stored on the at least one volume of storage, the computer system comprising at least first and second data paths extending between the at least one client device and the at least one storage system, the first data path passing through the at least one file system server so that the at least one client device exchanges information with the at least one storage system via the first path using the file system interface, the second data path not passing through the at least one file system server so that the client device exchanges information with the at least one storage system via the second path using a storage system interface presented by the at least one storage system, the I/O operation, generated by the at least one client device, that seeks to exchange the first set of information between the at least one client device and the at least one storage system; and

selecting between the first and second data paths for exchanging the first set of information between the at least one client device and the at least one storage system based at least in part on the determination of whether the I/O operation seeks to write at least some of the first set of information to the at least one storage system, wherein the second data path is selected if the I/O operation seeks to write at least some of the first set of information to the at least one storage system.

2. The method of claim 1, wherein path selection between the first data path and the second data path is performed by a path selection module of the at least one file system server.

3. The method of claim 2, wherein said selecting comprises transmitting to the at least one client device a second set of information comprising an indication of a selection between the first and second data paths.

4. The method of claim 1, wherein path selection between the first data path and the second data path is performed by a path selection module of the at least one client device.

5. The method of claim 1, wherein said selecting comprises selecting the first data path in response to a determination that the I/O operation seeks to read at least some of the first set of information from the at least one storage system.

6. A non-transitory computer-readable medium encoded with computer-executable instructions that, when executed, perform a method for use in a computer system, the method comprising:

determining whether an input/output (I/O) operation seeks to write at least some of a first set of information to at least one storage system, the computer system comprising at least one client device, the at least one storage system that provides at least one volume of storage to store information and at least one file system server that provides a file system interface for at least some of the information stored on the at least one volume of storage, the computer system comprising at least first and second data paths extending between the at least one client device and the at least one storage system, the first data path passing through the at least one file system server so that the at least one client device exchanges information with the at least one storage system via the first path using the file system interface, the second data path not passing through the at least one file system server so that the client device exchanges information with the at least one storage system via the second path using a storage system interface presented by the at least one storage system, the I/O operation, generated by the at least one client device, that seeks to exchange the first set of information between the at least one client device and the at least one storage system; and

selecting between the first and second data paths for exchanging the first set of information between the at least one client device and the at least one storage system based at least in part on the determination of whether the I/O operation seeks to write at least some of the first set of information to the at least one storage system, wherein the second data path is selected in response to a determination that the I/O operation seeks to write at least some of the first set of information to the at least one storage system.

7. The non-transitory computer-readable medium of claim 6, wherein a path selection module of the at least one file system server performs path selection between the first data path and the second data path.

8. The non-transitory computer-readable medium of claim 7, wherein said selecting comprises transmitting to the at least one client device a second set of information comprising an indication of a selection between the first and second data paths.

9. The non-transitory computer-readable medium of claim 7, wherein the first set of information is a file in a first file system managed by the at least one file system server, and wherein the I/O operation is an operation accessing the file.

10. The non-transitory computer-readable medium of claim 7, wherein the method further comprises receiving from the at least one client device an indication of a type of the I/O operation to be executed.

11. The non-transitory computer-readable medium of claim 6, wherein a path selection module of the client device performs path selection between the first data path and the second data path.

12. An apparatus for use in a computer system, the apparatus comprising:

at least one processor, wherein the computer system comprises at least one client device, at least one storage system that provides at least one volume of storage to store information and at least one file system server that provides a file system interface for at least some of the information stored on the at least one volume of storage, the computer system comprising at least first and second data paths extending between the at least one client device and the at least one storage system, the first data path passing through the at least one file system server so that the at least one client device exchanges information with the at least one storage system via the first path using the file system interface, the second data path not passing through the at least one file system server so that the client device exchanges information with the at least one storage system via the second path using a storage system interface presented by the at least one storage system, and wherein the at least one processor is programmed to, for an input/output (I/O) operation, generated by the at least one client device, that seeks to exchange a first set of information between the at least one client device and the at least one storage system;

determine whether the I/O operation seeks to write at least some of the first set of information to the at least one storage system; and

select between the first and second data paths for exchanging the first set of information between the at least one client device and the at least one storage system based on the determination of whether the I/O operation seeks to write at least some of the first set of information to the at least one storage system, wherein the at least one processor is programmed to select the second data path in response to a determination by the processor that the I/O operation seeks to write at least some of the first set of information to the at least one storage system.

13. The apparatus of claim 12, wherein the apparatus is the at least one file system server.

14. The apparatus of claim 13, wherein the at least one processor is further programmed to transmit to the at least one client device a second set of information comprising an indication of a selection between the first and second data paths.

15. The apparatus of claim 12, wherein the apparatus is the at least one client device.

16. The apparatus of claim 12, wherein the first data path comprises a first plurality of parallel links between the at least one client device and the at least one file system server;

wherein the second data path comprises a second plurality of parallel links between the client and the storage system; and

wherein selecting between the first and second data path comprises selecting the first or second data path without constraining the at least one client device to exchanging the first set of information via the selected data path over any one or more particular links of the first or second plurality of parallel links.