Network storage appliance with integrated redundant servers and storage controllers

• US 20050021606A1
• Filed: 04/23/2004
• Published: 01/27/2005
• Est. Priority Date: 04/23/2003
• Status: Active Grant

• Current Assignee: Dot Hill Systems Corporation (Seagate Technology Holdings Plc)
• Original Assignee: Dot Hill Systems Corporation (Seagate Technology Holdings Plc)
• Inventors: Davies, Ian Robert, Pecone, Victor Key, Kalwitz, George Alexander
• Granted Patent: US 7,330,999 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/2005 using redundant communication controllers
• CPC Class Codes: G06F 11/2007 using redundant communication media
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 11/2028 eliminating a faulty processor or activating a spare
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2046 where the redundant components share persistent storage G06F11/2043 takes precedence
• CPC Class Codes: G06F 11/2051 in regular structures
• CPC Class Codes: G06F 11/2092 Techniques of failing over between control units
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0673 Single storage device

Abstract

A network storage appliance is disclosed. The appliance includes a single chassis that encloses a plurality of servers and a plurality of storage controllers coupled together via a chassis backplane. The storage controllers control the transfer of data between the plurality of servers and a plurality of storage devices coupled to the storage controllers. The servers and storage controllers include a plurality of field replaceable unit (FRUs) hot-pluggable into the backplane such that any one of the FRUs may fail without loss of availability to the storage devices'"'"' data. In various embodiments, the chassis fits in a 19″ wide rack; is 1U high; the servers are standard PCs configured to execute off-the-shelf server applications and to facilitate porting of popular operating systems with little modification; the servers include disk-on-chip memory rather than a hard drive; local buses (e.g., PCIX) on the backplane interface the various FRUs.

Claims

1. A network storage appliance, comprising:

a chassis;

a backplane, enclosed in said chassis;

a plurality of servers, enclosed in said chassis, each coupled to said backplane; and

a plurality of storage controllers, enclosed in said chassis, each coupled to said backplane, for controlling transfer of data between said plurality of servers and a plurality of storage devices coupled to said plurality of storage controllers;

wherein said plurality of storage controllers and said plurality of servers comprise a plurality of hot-pluggable field replaceable units (FRUs), wherein any one of said plurality of FRUs may be replaced during operation of the appliance without loss of access to said plurality of storage devices.

2. The network storage appliance of claim 1, wherein said chassis comprises a chassis for mounting in a 19 inch wide rack.

3. The network storage appliance of claim 1, wherein said chassis is 1 U high.

4. The network storage appliance of claim 1, wherein said plurality of servers are redundant active-active servers.

5. The network storage appliance of claim 1, wherein said plurality of storage controllers are redundant active-active storage controllers.

6. The network storage appliance of claim 1, further comprising:

at least one power supply, enclosed in said chassis, for providing power to said plurality of FRUs.

7. The network storage appliance of claim 6, wherein said at least one power supply provides said power to said plurality of FRUs through said backplane.

8. The network storage appliance of claim 6, wherein said at least one power supply comprises a redundant plurality of power supplies, wherein at least one of said redundant plurality of power supplies may be replaced during operation of the appliance without loss of access to said plurality of storage devices.

9. The network storage appliance of claim 1, wherein each of said plurality of storage controllers and said plurality of servers plugs into a same side of said chassis.

10. The network storage appliance of claim 1, wherein each of said plurality of storage controllers is configured to receive from said plurality of servers input/output (I/O) requests and to control said transfer of data between said plurality of servers and said plurality of storage devices in response to said I/O requests.

11. The network storage appliance of claim 10, wherein said plurality of servers are configured to execute at least one storage software application for generating said I/O requests.

12. The network storage appliance of claim 1, wherein the appliance comprises a network attached storage (NAS) appliance.

13. The network storage appliance of claim 1, wherein the appliance comprises a storage area network (SAN) storage appliance.

14. The network storage appliance of claim 1, wherein the appliance is configured to receive data transfer requests from host computers coupled to the appliance externally from said chassis.

15. The network storage appliance of claim 14, wherein said data transfer requests comprise filesystem-level requests.

16. The network storage appliance of claim 14, wherein said data transfer requests comprise block-level input/output (I/O) requests.

17. The network storage appliance of claim 16, wherein said block-level input/output (I/O) requests comprise small computer systems interface (SCSI) requests.

18. The network storage appliance of claim 14, wherein said host computers are coupled to the appliance externally from said chassis via a FibreChannel network.

19. The network storage appliance of claim 14, wherein said host computers are coupled to the appliance externally from said chassis via an Ethernet network.

20. The network storage appliance of claim 14, wherein said host computers are coupled to the appliance externally from said chassis via an Infiniband network.

21. The network storage appliance of claim 1, wherein the appliance is a host-independent network storage appliance.

22. The network storage appliance of claim 21, wherein the host-independent network storage appliance receives power independent of host computers networked to the network storage appliance.

23. The network storage appliance of claim 21, wherein the host-independent network storage appliance is configured to boot independently of host computers networked to the network storage appliance.

24. The network storage appliance of claim 21, wherein the host-independent network storage appliance is configured to perform data transfers between said plurality of storage devices and host computers networked to the network storage appliance independent of which operating system is running on said host computers.

25. The network storage appliance of claim 1, further comprising:

a storage software application, executing on one or more of said plurality of servers.

26. The network storage appliance of claim 25, further comprising:

a solid state memory, for storing said storage software application.

27. The network storage appliance of claim 26, wherein said solid state memory comprises a disk-on-chip memory.

28. The network storage appliance of claim 25, wherein said storage software application comprises a data backup application for backing up data from a first of said plurality of storage devices to a second of said plurality of storage devices.

29. The network storage appliance of claim 28, wherein said second of said plurality of storage devices comprises a tape device.

30. The network storage appliance of claim 25, wherein said storage software application comprises a data backup application for backing up data from said plurality of storage devices to a first location physically remote from a second location of the network storage appliance.

31. The network storage appliance of claim 25, wherein said storage software application comprises a remote mirroring application.

32. The network storage appliance of claim 25, wherein said storage software application comprises a data snapshot application.

33. The network storage appliance of claim 25, wherein said storage software application comprises a storage virtualization application.

34. The network storage appliance of claim 25, wherein said storage software application comprises a file server application.

35. The network storage appliance of claim 1, wherein each of said plurality of storage controllers provides a communication path to each of said plurality of storage devices, wherein if one of said plurality of storage controllers fails, one or more remaining said plurality of storage controllers continues to provide access to said plurality of storage devices.

36. The network storage appliance of claim 1, wherein said plurality of storage controllers are configured to present a first set of logical storage devices for access by said plurality of servers and a second set of logical storage devices for access by a plurality of computer systems networked to said plurality of storage controllers, wherein said plurality of computer systems are external to said chassis.

37. The network storage appliance of claim 36, wherein said plurality of storage devices comprises said first and second set of logical storage devices.

38. The network storage appliance of claim 36, wherein said plurality of servers are configured to execute a storage application for presenting a said first set of logical storage devices in a virtualized manner for access by a second plurality of computer systems networked to said plurality of servers.

39. The network storage appliance of claim 1, further comprising:

a connector, affixed on the storage appliance, for enabling devices external to said chassis to access said plurality of storage controllers.

40. The network storage appliance of claim 39, wherein said devices external to said chassis comprise computers.

41. The network storage appliance of claim 39, wherein said devices external to said chassis comprise switches.

42. The network storage appliance of claim 39, wherein said devices external to said chassis comprise routers.

43. The network storage appliance of claim 39, wherein said connector is also configured to enable said plurality of servers to access said devices external to said chassis.

44. The network storage appliance of claim 43, wherein said devices external to said chassis comprise storage controllers.

45. The network storage appliance of claim 1, wherein said plurality of servers are comprised on two or less FRUs.

46. The network storage appliance of claim 1, wherein said plurality of servers are comprised on two or less blade modules.

47. The network storage appliance of claim 1, wherein each of said plurality of servers are comprised on a single blade module.

48. The network storage appliance of claim 1, wherein said plurality of storage controllers comprise redundant array of inexpensive disks (RAID) controllers.

49. The network storage appliance of claim 1, wherein said backplane comprises an active backplane.

50. The network storage appliance of claim 1, wherein said backplane comprises a passive backplane.

51. The network storage appliance of claim 1, further comprising:

a redundant cooling system for cooling said plurality of servers and said plurality of storage controllers.

52. The network storage appliance of claim 1, wherein each of said plurality of FRUs comprises:

a removal mechanism for use by a person to disconnect said FRU from said backplane for removal of said FRU from said chassis while said chassis is powered up.

53. The network storage appliance of claim 1, wherein each of said plurality of servers comprises:

a communication port, for coupling said plurality of servers to one another to determine whether one of said plurality of servers is no longer operable, to enable failover in response to determining one of said plurality of servers is no longer operable.

54. The network storage appliance of claim 53, wherein said communication ports comprise Ethernet ports.

55. The network storage appliance of claim 1, wherein said backplane comprises:

a plurality of local buses, for coupling said plurality of hot-pluggable FRUs to one another to facilitate data transfer therebetween.

56. The network storage appliance of claim 55, wherein each of said plurality of hot-pluggable FRUs are coupled to at least two of said plurality of local buses.

57. The network storage appliance of claim 55, wherein each of said plurality of hot-pluggable FRUs are redundantly coupled to said plurality of local buses for providing active-active failover operation.

58. The network storage appliance of claim 55, wherein said plurality of local buses comprise PCIX buses.

59. The network storage appliance of claim 1, wherein each of said plurality of servers comprises a diskless personal computer.

60. The network storage appliance of claim 1, wherein each of said plurality of servers comprises a central processing unit and a plurality of peripherals, wherein said plurality of peripherals substantially conform to the peripherals of a personal computer.

61. A method for providing data storage in a fault-tolerant manner, the method comprising:

executing a storage software application on redundant active-active failover servers enclosed in a chassis;

issuing data transfer requests, by the servers, to redundant active-active failover storage controllers enclosed in the chassis, in response to said executing;

detecting a failure of a first of the servers, by a second of the servers, after said issuing; and

failing over for the first of the servers, by the second of the servers, in response to said detecting the failure of the first of the servers.

62. The method of claim 61, wherein said failing over comprises the second of the servers responding to the data transfer requests.

63. The method of claim 61, wherein said failing over comprises the second of the servers taking over the identity of the first one of the servers.

64. The method of claim 61, wherein said executing the storage software application comprises executing a file server application.

65. The method of claim 61, wherein said executing the storage software application comprises executing a data backup application.

66. The method of claim 61, wherein said executing the storage software application comprises executing a remote mirroring application.

67. The method of claim 61, wherein said executing the storage software application comprises executing a data snapshot application.

68. The method of claim 61, wherein said executing the storage software application comprises executing a storage virtualization application.

69. The method of claim 61, further comprising:

detecting the failure of the first of the servers, by one of the storage controllers; and

killing the first of the servers, by the one of the storage controllers, in response to said detecting.

70. The method of claim 69, wherein said killing is performed prior to said failing over.

71. A method for transferring data in a storage area network, the method comprising:

issuing from a first server enclosed in a chassis to a first storage controller also enclosed in the chassis a first request to transfer first data from a storage device controlled by the first storage controller to the first server;

issuing from a second server enclosed in the chassis to a second storage controller also enclosed in the chassis a second request to transfer second data from the storage device to the second server;

removing a blade, of which the first storage controller is comprised, from a backplane enclosed in the chassis after said issuing from the first and second servers; and

providing by the second storage controller, in place of the first storage controller, to the first server the first data, after said removing the blade.

72. The method of claim 71, further comprising:

receiving, by the first server, from a computer networked to the first server a request to write data to the storage device;

issuing, by the first server, a request to the first storage controller to write the data to the storage device, in response to said receiving the request to write the data to the storage device; and

issuing, by the first server, a request to write the data to a computer remotely networked with the first server, in response to said receiving the request to write the data to the storage device.

73. A computer network, comprising:

a plurality of computers; and

a network storage appliance, networked to said plurality of computers, comprising;

a chassis, having a backplane enclosed therein;

a plurality of servers, enclosed in said chassis, each coupled to said backplane; and

a plurality of storage controllers, enclosed in said chassis, each coupled to said backplane, for controlling transfer of data between said plurality of servers and a plurality of storage devices coupled to said plurality of storage controllers;

wherein said plurality of storage controllers and said plurality of servers comprise a plurality of blades, any one which may be replaced in said backplane during operation of said appliance without loss of access to data stored on said plurality of storage devices by said plurality of computers.

74. The computer network of claim 73, wherein each of said plurality of servers is configured to detect a failure of one of said plurality of servers and to take over the identity of said failed one of said plurality of servers on a network coupling said plurality of computers and said network storage appliance in response to detecting said failure.

75. The computer network of claim 73, wherein each of said plurality of storage controllers is configured to detect a failure of one of said plurality of storage controllers and to take over the identity of said failed one of said plurality of storage controllers on a network coupling said plurality of computers and said network storage appliance in response to detecting said failure.

76. The computer network of claim 73, further comprising:

a heartbeat link, coupling said plurality of servers, for enabling said plurality of servers to provide a heartbeat to each other said plurality of servers, wherein each of said plurality of storage controllers is configured to detect a failure of said heartbeat link and to inactivate one of said plurality of servers in response to detecting said failure, thereby enabling a remaining one of said plurality of servers to take over the identity of said inactivated one of said plurality of servers on a network coupling said plurality of computers and said network storage appliance.

77. The computer network of claim 76, wherein said heartbeat link is enclosed in said chassis.

78. The computer network of claim 73, wherein each of said plurality of servers provides to each of said plurality of storage controllers a heartbeat, wherein said plurality of storage controllers are configured to detect a condition in which said heartbeat from one of said plurality of servers has stopped and to inactivate said one of said plurality of servers in response to detecting said condition.