RAID method and device with network protocol between controller and storage devices

• US 6,834,326 B1
• Filed: 03/17/2000
• Issued: 12/21/2004
• Est. Priority Date: 02/04/2000
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Lee, David C., Wang, Peter S. S.
• Primary Examiner(s): Padmanabhan, Mano
• Assistant Examiner(s): SONG, HUA JASMINE
• Application Number:
  US09/527,904
• Time in Patent Office: 1,740 Days
• Field of Search: 711/114, 711/4, 711/162, 711/161, 711/154, 709/200, 710/1, 370/351-356
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity

Abstract

The present invention relates to transparent access to a redundant array of inexpensive devices. In particular, it provides a method and device for connecting redundant disk drives to a controller, preferably an intelligent switch, via a network. The disks are controlled by commands transported across the network. Commands may be SCSI, IDE/ATA or other commands. The network may comprise ethernet, fiber channel or other physical layer protocol. Commands can be encapsulated in IP packets and transmitted using either a reliable or unreliable transport protocol. Multicasting of packets from the controller to the multiple disk drives is part of the present invention.

Claims

1. A device implementing mirrored storage across a network, including:

a disk controller configured to read and write mirrored storage devices;

a plurality of storage devices using a network protocol to communicate with the disk controller; and

logic cooperating with the disk controller to transmit a packet addressed to a group of storage devices and directing action by at least two of the storage devices;

wherein data returned by the storage devices in response to the packet is staggered.

2. The device of claim 1, wherein multiple commands are included in the packet.

3. The device of claim 2, wherein the packet includes commands compliant with one or more SCSI protocols.

4. The device of claim 1, wherein the network protocol includes transmitting the packet in an Ethernet packet.

5. The device of claim 1, wherein the network protocol includes communicating the packet using a fibre channel protocol.

6. The device of claim 1, wherein the network protocol includes encapsulating the packet in an IP packet.

7. The device of claim 6, wherein the network protocol further includes transporting the IP packet using UDP.

8. The device of claim 6, wherein the network protocol further includes transporting the IP packet using TCP.

9. The device of claim 1, wherein the packet includes commands compliant with one or more SCSI protocols.

10. A device implementing striped and parity guarded storage across a network, including:

a disk controller configured to read and write striped and parity storage devices;

three or more storage devices using a network protocol to communicate with the disk controller; and

logic cooperating with the disk controller to transmit a packet addressed to a group of storage devices and directing action by at least two of the storage devices;

wherein data returned by the storage devices in response to the packet is staggered.

11. The device of claim 10, wherein multiple commands are included in the transmitted packet.

12. The device of claim 11, wherein the packet includes commands compliant with one or more SCSI protocols.

13. The device of claim 10, wherein the network protocol includes placing packets in Ethernet packets.

14. The device of claim 10, wherein the network protocol includes communicating the packet using a fibre channel protocol.

15. The device of claim 10, wherein the network protocol includes encapsulating the packet in an IP packet.

16. The device of claim 15, wherein the network protocol further includes transporting the IP packets using UDP.

17. The device of claim 15, wherein the network protocol further includes transporting the IP packets using TCP.

18. The device of claim 15, wherein the packet includes commands compliant with one or more SCSI protocols.

19. A device implementing networked RAID, including:

a RAID controller;

a plurality of storage devices using a network protocol to communicate with the RAID controller; and

logic cooperating with the RAID controller to multicast a command packet from the RAID controller to the storage devices;

wherein data returned by the storage devices in response to the packet is staggered.

20. The device of claim 19, wherein multiple commands are included in the multicast command packet.

21. The device of claim 20, wherein the command packet includes commands compliant with one or more SCSI protocols.

22. The device of claim 19, wherein the RAID controller is implemented on a switch configured as a virtual storage device, comprising one or more input processors, logic to process packets, switch fabric, a forwarding table and one or more output processors.

23. The device of claim 22, wherein the switch further comprises a file system.

24. The device of claim 23, wherein the file system complies with a NFS protocol.

25. The device of claim 23, wherein the file system complies with a CIFS protocol.

26. The device of claim 19, wherein at least one of the storage devices is a switch configured as a virtual storage device.

27. The device of claim 19, wherein the network protocol includes placing the command packet in an Ethernet packet.

28. The device of claim 19, wherein the network protocol includes communicating the command packet using a fibre channel protocol.

29. The device of claim 19, wherein the network protocol includes encapsulating the command packet in an IP packet.

30. The device of claim 29, wherein the network protocol further includes transporting the IP packet using UDP.

31. The device of claim 29, wherein the network protocol further includes transporting the IP packet using TCP.

32. The device of claim 19, wherein the command packet includes commands compliant with one or more SCSI protocols.

33. A device implementing networked RAID, including:

a RAID controller;

a plurality of storage devices using a network protocol to communicate with the RAID controller; and

logic cooperating with the RAID controller to multicast a data packet from the RAID controller to the storage devices;

wherein data returned by the storage devices in response to the packet is staggered.

34. The device of claim 33, wherein the storage devices include forward error correction logic operative to correct errors in the data packet.

35. The device of claim 33, wherein the logic to multicast data packets includes logic to add forward error correction codes to the data packet.

36. The device of claim 33, wherein the logic to multicast data packet does not require confirmation of receipt from the storage devices.

37. The device of claim 33, wherein the RAID controller is implemented on a switch configured as a virtual storage device, comprising one or more input processors, logic to process packets, switch fabric, a forwarding table and one or more output processors.

38. The device of claim 37, wherein the switch further comprises a file system.

39. The device of claim 38, wherein the file system complies with a NFS protocol.

40. The device of claim 38, wherein the file system complies with a CIFS protocol.

41. The device of claim 33, wherein at least one of the storage devices is a switch configured as a virtual storage device.

42. The device of claim 33, wherein the network protocol includes placing the data packet in an Ethernet packet.

43. The device of claim 33, wherein the network protocol includes communicating the data packet using a fibre channel protocol.

44. The device of claim 33, wherein the network protocol includes encapsulating the data packet in an IP packet.

45. The device of claim 44, wherein the network protocol further includes transporting the IP packet using UDP.

46. The device of claim 44, wherein the network protocol further includes transporting the IP packet using TCP.

47. A method implementing networked mirrored storage, using a disk controller communicating by a network protocol with a plurality of storage devices, including the steps:

transmitting from a disk controller a command to read data, said command addressed to a group of storage devices and directing action by at least two storage devices; and

receiving data from the storage devices, wherein the data received in response to the read data command is staggered.

48. The method of claim 47, wherein the data being read is located at the same logical address within extents of two or more storage devices.

49. The method of claim 47, wherein the step of transmitting includes placing the command in an Ethernet packet.

50. The method of claim 47, wherein the step of transmitting includes communicating the command packet using a fibre channel protocol.

51. The method of claim 47, wherein the step of transmitting includes encapsulating the command packet in an IP packet.

52. The method of claim 51, wherein the step of transmitting further includes transporting the IP packet using UDP.

53. The method of claim 51, wherein the step of transmitting further includes transporting the IP packet using TCP.

54. The method of claim 51, wherein the command packet includes commands compliant with one or more SCSI protocols.

55. A device implementing mirrored storage across a network, including:

a disk controller configured to read and write mirrored storage devices;

a plurality of storage devices using a network protocol to communicate with the disk controller; and

logic cooperating with the disk controller to transmit a packet, said packet to be received and acted upon by at least two of the storage devices;

wherein the disk controller is implemented on a switch configured as a virtual storage device, comprising one or more input processors, logic to process packets, switch fabric, a forwarding table and one or more output processors.

56. The device of claim 55, wherein the switch further comprises a file system.

57. The device of claim 56, wherein the file system complies with a NFS protocol.

58. The device of claim 56, wherein the file system complies with a CIFS protocol.

59. A device implementing mirrored storage across a network, including:

a disk controller configured to read and write mirrored storage devices;

a plurality of storage devices using a network protocol to communicate with the disk controller; and

logic cooperating with the disk controller to transmit a packet, said packet to be received and acted upon by at least two of the storage devices;

wherein at least one of the storage devices is a switch configured as a virtual storage device.

60. A device implementing striped and parity guarded storage across a network, including:

a disk controller configured to read and write striped and parity storage devices;

three or more storage devices using a network protocol to communicate with the disk controller; and

logic cooperating with the disk controller to transmit a packet, said packet to be received and acted upon by at least two of the storage devices;

wherein the disk controller is implemented on a switch configured as a virtual storage device, comprising one or more input processors, logic to process packets, switch fabric, a forwarding table and one or more output processors.

61. The device of claim 60, wherein the switch further comprises a file system.

62. The device of claim 61, wherein the file system complies with a NFS protocol.

63. The device of claim 61, wherein the file system complies with a CIFS protocol.

64. A method implementing networked mirrored storage, using a disk controller communicating by a network protocol with a plurality of storage devices, including the steps:

transmitting from a disk controller a command to read data, said command to be received and acted upon by at least two storage devices;

receiving data from the storage devices; and

comparing the received data to verify its integrity;

wherein the disk controller is implemented on a switch configured as a virtual storage device, comprising one or more input processors, logic to process packets, switch fabric, a forwarding table and one or more output processors.

65. The method of claim 64, wherein the switch further comprises a file system.

66. The method of claim 65, wherein the file system complies with a NFS protocol.

67. The method of claim 65, wherein the file system complies with a CIFS protocol.

68. A method implementing networked mirrored storage, using a disk controller communicating by a network protocol with a plurality of storage devices, including the steps:

transmitting from a disk controller a command to read data, said command to be received and acted upon by at least two storage devices;

receiving data from the storage devices; and

comparing the received data to verify its integrity;

wherein at least one of the storage devices is a switch configured as a virtual storage device.

69. A device implementing striped and parity guarded storage across a network, including:

a disk controller configured to read and write striped and parity storage devices;

three or more storage devices using a network protocol to communicate with the disk controller; and

logic cooperating with the disk controller to transmit a packet, said packet to be received and acted upon by at least two of the storage devices;

wherein at least one of the storage devices is a switch configured as a virtual storage device.

70. A method implementing striped networked storage with parity, using a disk controller communicating by a network protocol with a plurality of storage devices, including:

transmitting from a disk controller a command to write data to three or more storage devices;

organizing data in accordance with a data striping and parity protocol; and

transmitting the organized data to the storage devices using a network protocol;

wherein the disk controller is implemented on a switch configured as a virtual storage device, comprising one or more input processors, logic to process packets, switch fabric, a forwarding table and one or more output processors.

71. The method of claim 70, wherein the switch further comprises a file system.

72. The method of claim 71, wherein the file system complies with a NFS protocol.

73. The method of claim 71, wherein the file system complies with a CIFS protocol.

74. A method implementing striped networked storage with parity, using a disk controller communicating by a network protocol with a plurality of storage devices, including:

transmitting from a disk controller a command to write data to three or more storage devices;

organizing data in accordance with a data striping and parity protocol; and

transmitting the organized data to the storage devices using a network protocol;

wherein at least one of the storage devices is a switch configured as a virtual storage device.