System and method of implementing disk ownership in networked storage

• US 20030120743A1
• Filed: 12/21/2001
• Published: 06/26/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Aster, Radek, Coatney, Susan M., Rowe, Alan L., Sarma, Joydeep Sen
• Granted Patent: US 7,650,412 B2
• Time in Patent Office: Days
• US Class Current: 709/217
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources

Abstract

A system and method for disk ownership in a network storage system. Each disk has two ownership attributes set to show that a particular file server owns the disk. In a preferred embodiment the first ownership attribute is the serial number of the file server being written to a specific location on each disk and the second ownership attribute is setting a SCSI-3 persistent reservation. In a system utilizing this disk ownership method, multiple file servers can read data from a given disk, but only the file server that owns a particular disk can write data to the disk.

Claims

1. A method for a network device to claim ownership of a disk in a network storage system comprising the steps of:

setting a first ownership attribute on the disk to a state of ownership by network device; and

setting a second ownership attribute on the disk to a state of ownership by network device.

2. The method of claim 1, wherein one of the first ownership attribute and the second ownership attribute further comprises a small computer system interface level 3 persistent reservation tag.

3. The method of claim 1, wherein one of the first ownership attribute and the second ownership attribute further comprises ownership information written on a predetermined area of the disk.

4. The method of claim 3, wherein the ownership information further comprises a serial number of the network device.

5. The method of claim 1, wherein the network device comprises a file server.

6. A method of claiming ownership of a disk by a network device in a network storage system comprising the steps of:

writing ownership information to a predetermined area of the disk; and

setting a small computer system interface level 3 persistent reservation tag to a state of network device ownership.

7. The method of claim 6 wherein the ownership information further comprises a serial number of a network device.

8. The method of claim 6, wherein the network device comprises a file server.

9. A network storage system comprising:

a plurality of network devices;

one or more switches, each network device connected to at least one of the one or more switch; and

a plurality of disks having a first ownership attribute and a second ownership attribute, each disk connected to at least one of the plurality of switches.

10. The network storage system of claim 9, wherein the first ownership attribute further comprises ownership information written on a predetermined area of the disk.

11. The network storage system of claim 9, wherein the second ownership attribute further comprises a small computer system interface level 3 persistent reservation tag.

12. The networked storage system of claim 11, wherein each disk that is owned by the network device has the small computer system interface level 3 persistent reservation set such that only the network device may write to the disk.

13. The network storage system of claim 10, wherein the ownership information further comprises of a serial number of the network device that owns that particular disk.

14. The network storage system of claim 10, wherein each of the plurality of file servers can read data from each of the plurality of disks.

15. The network storage system of claim 10, wherein only a network device that owns one of the plurality of disks can write data to the one disk.

16. The network storage system of claim 9, wherein the network devices comprise file servers.

17. A network storage system comprising:

one or more switches;

a plurality of disks; and

a plurality of network devices, each of the network devices including means for claiming ownership of one of the plurality of disks in the network storage system.

18. The network storage system of claim 17, wherein the means for claiming ownership further comprises:

means for writing ownership information to a predetermined area of a disk; and

means for setting a small computer system interface level 3 persistent reservation on a disk.

19. The network storage system of claim 17, wherein the network devices comprise file servers.

20. A network storage system comprising:

one or more switches interconnected to form a switching fabric;

a plurality of disks, each of the disks connected to at least one of the switches; and

one or more network devices, interconnected with the switching fabric, each of the network devices being adapted to own a predetermined set of disks of the plurality of disks.

21. The network storage system of claim 20, wherein the plurality of disks further comprises a first ownership attribute and a second ownership attribute.

22. The network storage system of claim 21, wherein the first ownership attribute is ownership information written to a predetermined area of each of the disks.

23. The network storage system of claim 22, wherein the ownership information further comprises a serial number of one of the one or more network devices.

24. The network storage system of claim 21, wherein the second ownership information is a small computer system interface level 3 persistent reservation.

25. The network storage system of claim 20, wherein each of the network devices further comprises a disk ownership table, the disk ownership table containing ownership data for each of the disks.

26. The network storage system of claim 25, wherein the ownership table further comprises a world wide name for each of the disks, the world wide name being used for identification of each of the disks.

27. A computer-readable medium, including program instructions executing on network device, for performing the steps of:

writing ownership information to a predetermined area of a disk; and

setting a small computer system interface level 3 persistent reservation tag to a state of network device ownership.