System and method for storing storage operating system data in switch ports

• US 7,987,323 B2
• Filed: 11/16/2006
• Issued: 07/26/2011
• Est. Priority Date: 12/20/2001
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Aster, Radek, Coatney, Susan M.
• Primary Examiner(s): Thai; Tuan V.
• Application Number:
  US11/600,474
• Publication Number:
  US 20070061526A1
• Time in Patent Office: 1,713 Days
• Field of Search: 711/114, 711147-148, 711/154, 711/100, 709/200, 709/212, 709/213, 709/214
• US Class Current: 711/154
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• 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

A computer server system and a method for operating the system are described. An address and a status of each computer device of a plurality of computer devices accessible to a switch is written into a memory in the switch. The status of a first computer device which is off line is set to indicate that the first computer device is off line. The status information is read from the memory in the switch by a second computer device so that the second computer device knows that the first computer device is off line. Embodiments are described where the status of a data storage device and the status of a server are written to the memory in the switch.

Claims

1. A method for operating a computer system, comprising:

writing a status of each data storage device of a plurality of data storage devices to a memory in a switch, an at least one server connected to the switch, and a selected data storage device of the plurality of data storage devices accessible through the switch by the at least one server;

changing the status of a data storage device which becomes off line to a changed status to indicate that the data storage device is off line;

providing an alert to the at least one server to read the changed status; and

reading the changed status from the memory in the switch by the at least one server in response to the alert before the at least one server transfers data to the selected data storage device in order to prevent the server from transferring data to the data storage device that is off line.

2. The method of claim 1, further comprising:

writing to the memory in the switch an address of each data storage device of the plurality of data storage devices.

3. The method of claim 1, further comprising:

writing to the memory in the switch an address and status of the at least one server so that an address of an offline server is available to other devices connected to the switch.

4. The method as in claim 1, further comprising:

using a port memory associated with a port of the switch as the memory in the switch.

5. The method as in claim 1, further comprising:

using a memory associated with a port of the switch to hold the status of a storage device accessible through the port.

6. The method as in claim 1, further comprising:

reading the changed status when a previously offline data storage device becomes online.

7. The method as in claim 1, further comprising:

using a disk as the data storage device.

8. The method as in claim 1, further comprising:

using a group of disks arranged as a RAID array as the storage device.

9. The method as in claim 1, further comprising:

causing by the alert the at least one server to re-read the memory in the switch to read the changed status.

10. A computer system, comprising:

an operating system to write an address and a status of each data storage device of a plurality of data storage devices to a memory in a switch, at least one server connected to the switch, and a selected data storage device of the plurality of data storage devices accessible through the switch by the at least one server;

a write command of the operating system to change the status of a data storage device which becomes off line to a changed status to indicate that the data storage device is off line;

providing an alert to the at least one server to read the changed status; and

a read command of the operating system to read the changed status from the memory in the switch by the at least one server in response to the alert before the at least one server transfers data to the selected data storage device in order to prevent the server from transferring data to the data storage device that is off line.

11. The system of claim 10, further comprising:

an address of each data storage device of the plurality of data storage devices written into the memory.

12. The system of claim 10, further comprising:

an address and status of each server of the at least one server written into the memory so that an address of an offline server is available to other devices connected to the switch.

13. The system of claim 10, further comprising:

a port memory associated with a port of the switch used as the memory in the switch.

14. The system of claim 10, further comprising:

a port memory associated with a port of the switch to hold the status of a storage device accessible through the port.

15. The system as in claim 10, further comprising:

the changed status read when a previously offline data storage device becomes online.

16. The system as in claim 10, further comprising:

a disk used as the data storage device.

17. The system as in claim 10, further comprising:

a group of disks arranged as a RAID array used as the storage device.

18. The system as in claim 10, further comprising:

the alert to cause the at least one server to re-read the memory in the switch to read the changed status.

19. A method for operating a computer server system, comprising:

writing an address and a status of each server of a plurality of servers to a memory in a switch;

setting the status of a first server which is off line to indicate that the first server is off line;

providing an alert to the plurality of servers to read the changed status; and

reading the changed status from the memory in the switch by a second server in response to the alert so that the second server knows that the first server is off line.

20. A computer system, comprising:

an operating system to write an address and a status of each server of a plurality of servers to a memory in a switch, and the operating system to set a changed status of a first server which is off line to indicate that the first server is off line;

the operating system to provide an alert to the plurality of servers to read the changed status; and

a second server to read, in response to the alert, the changed status from the memory in the switch so that the second server knows that the first server is off line.

21. A method for operating a computer server system, comprising:

writing an address and a status of each computer device of a plurality of computer devices accessible to a switch into a memory in the switch;

changing the status of a first computer device which is off line to a changed status to indicate that the first computer device is off line;

providing an alert to the at least one server to read the changed status; and

reading the changed status from the memory in the switch by a second computer device in response to the alert so that the second computer device knows that the first computer device is off line.

22. The method of claim 21, further comprising:

using a data storage device as the computer device.

23. The method of claim 21, further comprising:

using a server as the computer device.

24. A computer system, comprising:

an operating system to write an address and a status of each computer device of a plurality of computer devices to a memory in a switch, the computer devices accessible to the switch, and the operating system to set the status of a first computer device which is off line to indicate that the first computer device is off line;

the operating system to provide an alert to the plurality of computer devices to read the changed status; and

a read command to read the changed status from the memory in the switch in response to the alert so that a second computer device knows that the first computer device is off line.

25. The system of claim 24, further comprising:

a data storage device is the computer device.

26. The system of claim 24, further comprising:

a server is the computer device.

27. A computer readable storage media, comprising:

said computer readable media containing instructions for execution on a processor for the practice of a method for operating a computer server system, the method,

writing an address and a status of each computer device of a plurality of computer devices accessible to a switch into a memory in the switch;

changing the status of a first computer device which is off line to a changed status to indicate that the first computer device is off line;

providing an alert to the first computer device to read the changed status; and

reading the changed status from the memory in the switch by a second computer device in response to the alert so that the second computer device knows that the first computer device is off line in order to prevent the second computer device from transferring data to the first computer device that is off line.

28. The The computer readable storage media of claim 27, wherein the method further comprises:

using a data storage device as at least one of the plurality of the computer devices.

29. The computer readable storage media of claim 27, wherein the method further comprises:

using a server as at least one of the plurality of the computer devices.

30. A method for operating a computer system, comprising:

writing a status of each data storage device of a plurality of data storage devices to a memory in a switch, the plurality of data storage devices connected to the switch, and a processor connected to the switch;

changing the status of an identified data storage device of the plurality of data storage devices which becomes off line to a changed status to indicate that the identified data storage device is off line; and

reading by the processor the status of a selected data storage device from the memory in the switch before the processor transfers data to the selected data storage device, in order to prevent the server from transferring data to an off line data storage device.

31. The method of claim 30, further comprising:

writing to the memory in the switch an address of each data storage device of the plurality of data storage devices.

32. The method as in claim 30, further comprising:

using a port memory associated with a port of the switch as the memory in the switch.

33. The method as in claim 30, further comprising:

using a memory associated with a port of the switch to hold the status of a storage device accessible through the port.

34. A computer system, comprising:

a processor;

an operating system executing on the processor to write a status of each data storage device of a plurality of data storage devices to a memory in a switch, the plurality of data storage devices connected to the switch, and a the processor connected to the switch;

the operating system configured to change the status of an identified data storage device of the plurality of data storage devices which becomes off line to a changed status to indicate that the identified data storage device is off line; and

the processor to read the status of a selected data storage device from the memory in the switch before the server transfers data to the selected data storage device, in order to prevent the server from transferring data to an off line data storage device.

35. The computer system of claim 34, further comprising:

the memory in the switch having an address of each data storage device of the plurality of data storage devices.

36. The computer system as in claim 34, further comprising:

a port memory associated with a port of the switch used as the memory in the switch.

37. The computer system as in claim 34, further comprising:

a memory associated with a port of the switch used to hold the status of a storage device accessible through the port.

38. A computer readable storage media, comprising:

said computer readable media containing instructions for execution on a processor for the practice of a method for operating a computer system, the method, writing a status of each data storage device of a plurality of data storage devices to a memory in a switch, the plurality of data storage devices connected to the switch, and a server connected to the switch;

changing the status of an identified data storage device of the plurality of data storage devices which becomes off line to a changed status to indicate that the identified data storage device is off line; and

reading by the server the status of a selected data storage device from the memory in the switch before the server transfers data to the selected data storage device, in order to prevent the server from transferring data to an off line data storage device.