Virtual ports for partitioning of data storage

• US 20020194294A1
• Filed: 05/06/2002
• Published: 12/19/2002
• Est. Priority Date: 06/29/1998
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Steven M. Blumenau, Yoav Raz
• Inventors: Blumenau, Steven M., Raz, Yoav
• Granted Patent: US 6,988,130 B2
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0662 Virtualisation aspects
• 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 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A storage controller has at least one physical data port for a data network including host processors. The storage controller is programmed to provide a plurality of virtual ports for access to storage, and a virtual switch for routing storage access requests from the physical port to the virtual ports. The virtual ports and the virtual switch are defined by software. The virtual ports appear to the hosts as physical ports in the data network. For example, in a Fiber-Channel network, the virtual ports have World Wide Names (WWNs) and are assigned temporary addresses (S_IDs), and the virtual switch provides a name server identifying the WWNs and S_IDs of the virtual ports. For convenient partitioning of storage among host processors, one or more virtual ports are assigned to each host, and a set of storage volumes are made accessible from each virtual port.

Claims

1. A data storage subsystem comprising, in combination:

data storage; and

a storage controller coupled to the data storage for controlling access to the data storage, the storage controller having at least one physical data port for connecting the storage controller into a data network for data transmission between the data storage and host processors in the data network, wherein the storage controller is programmed to provide a plurality of virtual ports that are not physical ports in the data network but that appear to the host processors to be physical ports in the data network that provide access to the data storage and that are connected to the physical data port by a switch in the storage controller for routing storage access requests from the physical data port to the virtual ports.

2. The data storage subsystem as claimed in claim 1, wherein the virtual ports and the switch are defined by software contained in the storage controller.

3. The data storage subsystem as claimed in claim 1, wherein the storage controller is programmed with a permanent network name for each of the virtual ports, is programmed with a temporary network address for each of the virtual ports, and is programmed to route from the physical data port to a specified virtual port a storage access request containing a temporary address that specifies the specified virtual port.

4. The data storage subsystem as claimed in claim 1, wherein the storage controller is programmed so that the virtual ports and the switch are substantially compliant with Fibre-Channel network standards applicable to Fibre-Channel physical ports and Fibre-Channel fabric.

5. The data storage subsystem as claimed in claim 1, wherein the storage controller is programmed to provide a name server for responding to a name server request from the network by identifying the virtual ports and providing network addresses of the virtual ports.

6. The data storage subsystem as claimed in claim 1, wherein the storage controller is programmed to provide access at each virtual port to only a respective assigned subset of the data storage.

7. The data storage subsystem as claimed in claim 6, wherein the storage controller is programmed to permit no more than a respective assigned one of the host processors to access the subset of the data storage accessible from said each virtual port.

8. The data storage subsystem as claimed in claim 6, wherein the storage controller is programmed to as sign a host processor to each virtual port and to establish a respective mapping at said each virtual port between logical unit numbers addressable by the assigned host processor and corresponding storage volumes which the assigned host processor may access from said each virtual port.

9. The data storage subsystem as claimed in claim 6,+wherein the storage controller is programmed to assign a respective set of the virtual ports to each host processor, and to permit each host processor to access the subset of the data storage accessible from said each virtual port only when the respective set of virtual ports assigned to said each host processor contains said each virtual port.

10. The data storage subsystem as claimed in claim 9, wherein the storage controller is programmed to provide a facility for reporting to a host processor the virtual ports from which the host processor may access the data storage, and the subset of the data storage that the host processor may access from each of the virtual ports from which the host processor may access the data storage.

11. The data storage subsystem as claimed in claim 1, wherein the storage controller is programmed to assign a respective set of virtual ports to each host processor, and to permit said each host processor to access the storage from each virtual port only when the respective set of virtual ports assigned to said each host processor contains said each virtual port.

12. The data storage subsystem as claimed in claim 11, wherein the storage controller is programmed to permit only one respective assigned host processor to access the data storage from each virtual port.

13. The data storage subsystem as claimed in claim 11, wherein at least one respective set of virtual ports assigned to at least one host processor includes a first virtual port from which said at least one host processor can access private storage that is not shared with any other host processor, and a second virtual port from which said at least one host processor can access storage that is shared with another host processor.

14. The data storage subsystem as claimed in claim 1, wherein the storage controller is programmed with a directory of the virtual ports, wherein the directory includes an indication of whether or not only private storage is accessible from each virtual port, and the program is executable by the storage controller to respond to a storage access request for access to specified storage accessible from said each virtual port by checking said indication, and if said indication does not indicate that only private storage is accessible from said each virtual port, then accessing a storage locking facility to check whether or not the specified storage is already locked, and if said indication indicates that only private storage is accessible from said each virtual port, then not accessing the storage locking facility for checking whether or not the specified storage is already locked.

16. The machine-readable program storage device as claimed in claim 15, wherein the virtual ports and the switch are defined by the program.

17. The machine-readable program storage device as claimed in claim 15, wherein the program is executable by the storage controller so that each of the virtual ports has a permanent network name, and each of the virtual ports is assigned a temporary network address, and the program is executable to route from the physical data port to a specified virtual port a storage access request containing a temporary address that specifies the specified virtual port.

18. The machine-readable program storage device as claimed in claim 15, wherein the program is executable by the storage controller so that the virtual ports and the switch are substantially compliant with Fibre-Channel network standards applicable to Fibre-Channel physical ports and Fibre-Channel fabric.

19. The machine-readable program storage device as claimed in claim 15, wherein the program is executable by the storage controller to provide a name server for responding to a name server request from the network by identifying the virtual ports and providing network addresses of the virtual ports.

20. The machine-readable program storage device as claimed in claim 15, wherein the program is executable by the storage controller to provide access at each virtual port to only a respective assigned subset of the data storage.

21. The machine-readable program storage device as claimed in claim 20, wherein the program is executable by the storage controller to permit no more than a respective assigned one of the host processors to access the subset of the data storage accessible from said each virtual port.

22. The machine-readable program storage device as claimed in claim 20, wherein the program is executable by the storage controller to assign a host processor to each virtual port and to establish a respective mapping at said each virtual port between logical unit numbers addressable by the assigned host processor and corresponding storage volumes which the assigned host processor may access from said each virtual port.

23. The machine-readable program storage device as claimed in claim 20, wherein the program is executable by the storage controller to assign a respective set of the virtual ports to each host processor, and to permit each host processor to access the subset of the data storage accessible from said each virtual port only when the respective set of virtual ports assigned to said each host processor contains said each virtual port.

24. The machine-readable program storage device as claimed in claim 23, wherein the program is executable by the storage controller to provide a facility for reporting to a host processor the virtual ports from which the host processor may access the data storage, and the subset of the data storage that the host processor may access from each of the virtual ports from which the host processor may access the data storage.

25. The machine-readable program storage device as claimed in claim 15, wherein the program is executable by the storage controller to assign a respective set of virtual ports to each host processor, and to permit said each host processor to access the storage from each virtual port only when the respective set of virtual ports assigned to said each host processor contains said each virtual port.

26. The machine-readable program storage device as claimed in claim 25 wherein the program is executable by the storage controller to permit only one respective assigned host processor to access the data storage from each virtual port.

27. The machine-readable program storage device as claimed in claim 25, wherein the program is executable by the storage controller to assign to at least one host processor a first virtual port from which said at least one host processor can access private storage that is not shared with any other host processor, and to assign to said at least one host processor a second virtual port from which said at least one host processor can access storage that is shared with another host processor.

28. The machine-readable program storage device as claimed in claim 15, wherein the program is executable by the storage controller to maintain in the storage controller a directory of the virtual ports, wherein the directory includes an indication of whether or not only private storage is accessible from each virtual port, and the program is executable by the storage controller to respond to a storage access request for access to specified storage accessible from said each virtual port by checking said indication, and if said indication does not indicate that only private storage is accessible from said each virtual port, then accessing a storage locking facility to check whether or not the specified storage is already locked, and if said indication indicates that only private storage is accessible from said each virtual port, then not accessing the storage locking facility for checking whether or not the specified storage is already locked.

30. The method as claimed in claim 29, wherein the storage controller receives data from and transmits data to the network in such a way that the virtual ports and the switch are substantially compliant with Fibre-Channel network standards applicable to Fibre-Channel physical ports and Fibre-Channel fabric.

31. The method as claimed in claim 29, wherein the storage controller responds to a name server request from the network by identifying the virtual ports and providing network addresses of the virtual ports.

32. The method as claimed in claim 29, wherein the storage controller provides access at each virtual port to only a respective assigned subset of the data storage.

33. The method as claimed in claim 32, wherein the storage controller permits no more than a respective assigned one of the host processors to access the subset of the data storage accessible from said each virtual port.

34. The method as claimed in claim 32, wherein the storage controller assigns a host processor to each virtual port and establishes a respective mapping at said each virtual port between logical unit numbers addressable by the assigned host processor and corresponding storage volumes which the assigned host processor may access from said each virtual port.

35. The method as claimed in claim 32, wherein the program is executable by the storage controller to assign a respective set of the virtual ports to each host processor, and to permit each host processor to access the subset of the data storage accessible from said each virtual port only when the respective set of virtual ports assigned to said each host processor contains said each virtual port.

36. The method as claimed in claim 35, wherein the storage controller reports to a host processor the virtual ports from which the host processor may access the data storage, and the subset of the data storage that the host processor may access from each of the virtual ports from which the host processor may access the data storage.

37. The method as claimed in claim 29, wherein the storage controller assigns a respective set of virtual ports to each host processor, and permits said each host processor to access the storage from each virtual port only when the respective set of virtual ports assigned to said each host processor contains said each virtual port.

38. The method as claimed in claim 37, wherein the storage controller permits only one respective assigned host processor to access the data storage from each virtual port.

39. The method as claimed in claim 37, wherein the storage controller assigns to at least one host processor a first virtual port from which said at least one host processor can access private storage that is not shared with any other host processor, and to assign to said at least one host processor a second virtual port from which said at least one host processor can access storage that is shared with another host processor.

40. The method as claimed in claim 29, wherein the storage controller maintains a directory of the virtual ports, wherein the directory includes an indication of whether or not only private storage is accessible from each virtual port, and the storage controller responds to a storage access request for access to specified storage accessible from said each virtual port by checking said indication, and if said indication does not indicate that only private storage is accessible from said each virtual port, then accessing a storage locking facility to check whether or not the specified storage is already locked, and if said indication indicates that only private storage is accessible from said each virtual port, then not accessing the storage locking facility for checking whether or not the specified storage is already locked.

15. A machine-readable program storage device containing a program that is executable by a storage controller for controlling access to data storage, the storage controller having at least one physical data port for connecting the storage controller into a data network for data transmission between the data storage and host processors in the data network,

wherein the program is executable by the storage controller to provide a plurality of virtual ports that are not physical ports in the data network but that appear to the host processors to be physical ports in the data network that provide access to the data storage and that are connected to the physical data port by a switch in the storage controller for routing storage access requests from the physical data port to the virtual ports.

29. A method of operating a storage controller for controlling access to data storage, the storage controller having at least one physical data port for connecting the storage controller into a data network for data transmission between the data storage and host processors in the data network, said method comprising:

the storage controller receiving storage access requests from the host processors at the physical data port, and inspecting network addresses in the storage access requests to find network addresses of virtual ports in the storage controller to which the storage access requests are directed, and controlling access to the data storage in accordance with the network addresses of the virtual ports to which the storage access requests are directed, wherein the virtual ports are not physical data ports in the data network, but the storage controller is operated to cause the virtual ports to appear to the host processors to be physical ports in the data network that provide access to the data storage and that are connected to the physical data port by a switch in the storage controller for routing storage access requests from the physical port to the virtual ports.