STORAGE ROUTER AND METHOD FOR PROVIDING VIRTUAL LOCAL STORAGE

• US 20080307444A1
• Filed: 11/29/2007
• Published: 12/11/2008
• Est. Priority Date: 12/31/1997
• Status: Active Grant

• Current Assignee: Crossroads Systems (Texas) Incorporated (Crossroads Systems, Inc.)
• Original Assignee: Crossroads Systems (Texas) Incorporated (Crossroads Systems, Inc.)
• Inventors: Russell, Jeffry T., Hoese, Geoffrey B.
• Granted Patent: US 7,984,221 B2
• Time in Patent Office: Days
• US Class Current: 719/326
• CPC Class Codes: G06F 13/1668 Details of memory controller
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 13/4059 where the synchronisation uses buffers, e.g. for speed matching between buses
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• 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 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: H04L 2101/631 Small computer system interface [SCSI] addresses
• CPC Class Codes: H04L 2101/645 Fibre channel identifiers
• CPC Class Codes: H04L 61/106 across networks, e.g. mapping telephone numbers to data network addresses
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A storage router (56) and storage network (50) provide virtual local storage on remote SCSI storage devices (60, 62, 64) to Fibre Channel devices. A plurality of Fibre Channel devices, such as workstations (58), are connected to a Fibre Channel transport medium (52), and a plurality of SCSI storage devices (60, 62, 64) are connected to a SCSI bus transport medium (54) The storage router (56) interfaces between the Fibre Channel transport medium (52) and the SCSI bus transport medium (54). The storage router (56) maps between the workstations (58) and the SCSI storage devices (60, 62, 64) and implements access controls for storage space on the SCSI storage devices (60, 62, 64). The storage router (56) then allows access from the workstations (58) to the SCSI storage devices (60, 62, 64) using native low level, block protocol in accordance with the mapping and the access controls.

Claims

1. A storage router for providing virtual local storage on remote storage devices to iSCSI devices, comprising:

a buffer providing memory work space for the storage router;

a first controller operable to connect to and interface with a serial transport medium operable to transport an iSCSI protocol communication;

a second controller operable to connect to and interface with a second transport medium; and

a supervisor unit coupled to the first controller, the second controller and the buffer, the supervisor unit operable to map between iSCSI devices connected to the serial transport medium and the storage devices connected to the second transport medium, to implement access controls for storage space on the storage devices, and to process data in the buffer to interface between the first controller and the second controller to allow access between iSCSI devices connected to the serial transport medium and the storage devices through using low level, block protocols.

2. The storage router of claim 1, wherein the supervisor unit maintains an allocation of subsets of storage space to associated iSCSI devices connected to the serial transport medium, wherein each subset is only accessible by the associated iSCSI device.

3. The storage router of claim 2, wherein the storage router is further operable to receive an iSCSI protocol communication from the host device at the first controller, access the map to determine if the host device is allowed access to the subset of storage space for which the iSCSI protocol communication is intended, and send a low level block protocol command within the iSCSI protocol communication to the intended subset of the storage space if the host device is determined to be allowed access.

4. The storage router of claim 1, wherein the serial transport medium is an Ethernet transport medium, and wherein the first controller receives an iSCSI communication from the iSCSI device, the iSCSI communication comprising SCSI command, and the supervisor unit forwards the allowed SCSI commands to the storage devices.

5. The storage router of claim 3, wherein the storage devices comprise SCSI, Fibre Channel, ATA, SATA or Serial Attached SCSI storage devices.

6. The storage router of claim 5, wherein the supervisor unit forwards a low level block protocol command to the storage devices.

7. A method for providing virtual local storage on remote storage devices to iSCSI devices connected to a serial transport medium, comprising:

interfacing with the serial transport medium;

interfacing with a second transport medium;

mapping between iSCSI devices connected to the serial transport medium and the storage devices;

implementing access controls for storage space on the storage devices in accordance with the mapping; and

allowing access from iSCSI devices connected to the serial transport medium to the storage devices through using low level, block protocols.

8. The method of claim 7, wherein mapping between iSCSI devices connected to the serial transport medium and the storage devices includes allocating subsets of storage space to associated iSCSI devices, wherein each subset of storage space is only accessible by the associated iSCSI device.

9. The method claim 8, further comprising:

receiving an iSCSI protocol communication from the host device at the first controller;

accessing the map to determine if the host device is allowed access to the subset of storage space for which the iSCSI protocol communication is intended; and

sending a low level block protocol command within the iSCSI protocol communication to the intended subset of the storage space if the host device is determined to be allowed access to the intended subset of storage space.

10. The method of claim 9, wherein the storage devices comprise SCSI, Fibre Channel, ATA, SATA or Serial Attached SCSI storage devices.

11. A routing device for providing virtual local storage on remote storage devices to an iSCSI host device, comprising:

a first controller operable to communicate with an iSCSI transport medium;

a second controller operable to communicate with a second transport medium; and

a supervisor unit in communication with the first and second controllers, the supervisor unit operable to;

maintain a map that maps between the iSCSI host device and at least a portion of a first storage device, the map comprising a representation of the iSCSI host device and a representation of at least a portion of a first storage device; and

control access between the iSCSI host device and the first storage device in accordance with the map to allow the iSCSI host device to access the at least a portion of the first storage device through a low level block protocol.

12. The routing device of claim 11, wherein, for a request received from the iSCSI host device, the supervisor unit is further operable to:

access the map to determine whether the iSCSI host device is allowed access to the intended storage space on the at least a portion of the first storage device using a host identification for the iSCSI host device;

forward the request to the first storage device according to the low level block protocol.

13. The routing device of claim 12, wherein the map further maps between the iSCSI host device and at least a portion of a second storage device.

14. The routing device of claim 13, wherein the map further maps between at least one other iSCSI host device and the at least a portion of one of either the first storage device or the second storage device.

15. The routing device of claim 11, wherein the iSCSI transport medium is an Ethernet transport medium, wherein the low level block protocol is SCSI, wherein the SCSI low level block protocol is encapsulated in an iSCSI transport protocol on the iSCSI transport medium, and wherein the first controller receives an iSCSI communication from the iSCSI device and the supervisor unit forwards the allowed SCSI commands to the storage devices.

16. The routing device of claim 11, wherein the storage devices comprise SCSI, Fibre Channel, ATA, SATA or Serial Attached SCSI storage devices and wherein the supervisor unit forwards a low level block protocol command to the storage devices.

17. The routing device of claim 11, wherein the supervisor unit maintains an allocation of subsets of storage space to associated host devices connected to the iSCSI transport medium, wherein each subset is only accessible by the associated host device connected to the iSCSI transport medium.

18. The routing device of claim 11, wherein, for the iSCSI host device, the map maps from a host identification for the iSCSI host device to either a virtual or physical address for the at least a portion of the first storage device.

19. The routing device of claim 11, wherein the routing device provides virtual local storage on the remote storage devices by presenting the storage devices to the iSCSI host device as if the remotely located storage devices were within or locally attached to the iSCSI host device such that remote storage devices have the appearance of local storage.

20. The routing device of claim 19, wherein, for each iSCSI host device and each portion of each storage device, the map creates a path between each iSCSI host device and each portion of each storage device to which each particular iSCSI host device is allowed access by associating a unique identifier for iSCSI host device with a either a logical unit number or a physical identifier for each permitted portion of the storage device.

21. The routing device of claim 11, wherein the first storage device is a SCSI storage device.

22. The routing device of claim 11, wherein the first storage device is a Fibre Channel storage device.

23. The routing device of claim 11, wherein the first storage device is an ATA storage device.

24. The routing device of claim 11, wherein the first storage device is a SATA storage device.

25. The routing device of claim 11, wherein the first storage device is a SAS storage device.

26. A routing device for providing virtual local storage on a remote storage device to an iSCSI initiator device, comprising:

a first controller to communicate with a iSCSI transport medium connected to the iSCSI initiator device;

a second controller communicate with a second transport medium connected to the storage device; and

a supervisor unit in communication with the first and second controllers, the supervisor unit operable;

to maintain a map between the iSCSI initiator device and the storage device; and

to allow access from the iSCSI initiator device to the storage device using low level, block protocol in accordance with the map to implement access controls for storage space on the storage device.

27. The routing device of claim 26, wherein the map is implemented through one or more tables stored in memory at the routing device.

28. The routing device of claim 26, wherein the map that allocates subsets of storage space on the storage device to the iSCSI initiator device, wherein the subset is only accessible by the iSCSI initiator device.

29. The routing device of claim 26, wherein the storage device is located in excess of 1000 meters from the iSCSI initiator device.

30. The routing device of claim 26, wherein second transport medium is a SCSI transport medium.

31. The routing device of claim 26, wherein the second transport medium is a Fibre Channel transport medium.

32. The routing device of claim 26, wherein the second transport medium is an ATA transport medium.

33. The routing device of claim 26, wherein the second transport medium is a SATA transport medium.

34. The routing device of claim 26, wherein the second transport medium is a SAS transport medium.

35. A method for providing virtual local storage on remote storage devices to iSCSI devices, comprising:

maintaining a configuration for storage devices connected to a first transport medium that maps between iSCSI devices connected to an iSCSI transport medium and the storage devices and that implements access controls for storage space on the storage devices; and

allowing access from iSCSI initiator devices to storage devices using low level, block protocol and in accordance with the configuration.

36. The method of claim 35, wherein maintaining the configuration includes allocating subsets of storage space to associated iSCSI devices, wherein each subset is only accessible by the associated iSCSI device.

37. The method of claim 35, wherein maintaining the configuration further comprises maintaining a map that maps between unique identifiers associated with each of the iSCSI devices to unique identifiers associated with the storage devices.

38. The method of claim 37, wherein the map is maintained as one or more tables in a memory.

39. The method of claim 35, wherein the configuration comprises a map that maps between unique identifiers that provide a representation of the iSCSI storage device and virtual LUNs that provide a representation of the storage device.

40. A storage network, comprising:

an iSCSI transport medium;

a second transport medium;

a plurality of iSCSI workstations connected to the iSCSI transport medium;

a plurality of storage devices connected to the second transport medium; and

a routing device interfacing between the iSCSI transport medium and the second transport medium, the routing device providing virtual local storage on the storage devices to the workstations and operable;

to map between the iSCSI workstations and the storage devices;

to implement access controls for storage space on the storage devices; and

to allow access from the iSCSI workstations to the storage devices using low level, block protocol in accordance with the mapping and access controls.

41. The storage network of claim 40, wherein the access controls include an allocation of subsets of storage space to associated iSCSI workstations, wherein each subset is only accessible by the associated iSCSI workstation.

42. The storage network of claim 40, wherein the map creates a path between unique identifiers associated with each of the iSCSI devices to unique identifiers associated with the storage devices.

43. The storage network of claim 40, wherein the routing device comprises:

a buffer providing memory work space for the storage router;

a first controller operable to communicate with the iSCSI transport medium, the first controller further operable to pull outgoing data from the buffer and to place incoming data into the buffer;

a second controller operable to communicate with the second transport medium, the second controller further operable to pull outgoing data from the buffer and to place incoming data into the buffer; and

a supervisor unit in communication with the first and second controllers and the buffer, the supervisor unit operable;

to maintain a configuration for the storage devices that maps between iSCSI workstations and storage devices and that implements the access controls for storage space on the storage devices; and

to process data in the buffer to interface between the first controller and the second controller to allow access from workstations to storage devices in accordance with the configuration.

44. The storage network of claim 40, wherein the storage devices comprise SCSI storage devices.

45. The storage network of claim 40, wherein the storage devices comprise Fibre Channel storage devices.

46. The storage network of claim 40, wherein the storage devices comprise ATA storage devices.

47. The storage network of claim 40, wherein the storage devices comprise SATA storage devices.

48. The storage network of claim 40, wherein the storage devices comprise SAS storage devices.