Spanning virtual arrays across multiple physical storage arrays

• US 7,685,395 B1
• Filed: 06/29/2006
• Issued: 03/23/2010
• Est. Priority Date: 12/27/2005
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Ofer, Adi, Madnani, Kiran, Brown, Jeffrey A.
• Primary Examiner(s): Nguyen; Hiep T
• Application Number:
  US11/427,646
• Time in Patent Office: 1,363 Days
• Field of Search: None
• US Class Current: 711/170
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0637 Permissions
• 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 3/0689 Disk arrays, e.g. RAID, JBOD
• 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]

Abstract

Described are a storage network and method of presenting a virtual array in the storage network. The storage network includes a first storage array and a second storage array. At least one of the first and second storage arrays has one or more logical units of storage assigned to a virtual array that spans the first and second storage arrays. In addition, at least one of the first and second storage arrays has one or more physical ports coupled to the virtual array. The virtual array is assigned a unique virtual port identifier (ID) for each physical port coupled to the virtual array. A host coupled to a switch can communicate with the virtual array using a virtual port ID assigned to the virtual array.

Claims

1. A storage network comprising:

a first storage array and a second storage array, at least one of the first and second storage arrays having one or more logical units of storage assigned to a virtual array that spans the first and second storage arrays, at least one of the first and second storage arrays having one or more physical ports coupled to the virtual array, the virtual array being assigned a unique virtual port identifier (ID) for each physical port coupled to the virtual array.

2. The storage network of claim 1, further comprising a communication link between the first storage array and the second storage array, each of the first storage array and the second storage array redirecting an input/output (I/O) request, received by that storage array, over the communication link to the other storage array when the I/O request is addressed to a logical unit of the other storage array.

3. The storage network of claim 1, further comprising a Fibre Channel switch coupled to each physical port.

4. The storage network of claim 3, wherein the virtual port IDs are assignable by the switch.

5. The storage network of claim 3, wherein a virtual port ID is used by a host coupled to the switch to exchange data with the virtual array using one of the assigned virtual port IDs.

6. The storage network of claim 3, wherein the switch to which the virtual array can be coupled comprises:

a plurality of ports, each port being coupled to a host; and

a zoning table associating each virtual port ID to one of the ports.

7. The storage network of claim 6, wherein the virtual array communicates only with a host coupled to a port associated with one of the virtual port IDs assigned to the virtual array.

8. The storage network of claim 1, wherein the virtual array spans more than two storage arrays.

9. A method of presenting a virtual array in a storage network, the method comprising:

arranging at least one logical unit of storage in at least one of a first storage array and a second storage array into a virtual array that spans the first and second storage arrays;

coupling the virtual array to a switch through at least one physical port of at least one of the first and second storage arrays; and

assigning to the virtual array a unique virtual port identifier (ID) for each physical port that couples the virtual array to the switch.

10. The method of claim 9, further comprising the steps of:

receiving an input/output (I/O) request by one of the first and second storage arrays;

determining that the I/O request is addressed to a logical unit of the other of the first and second storage arrays; and

forwarding the I/O request to the other of the first and second storage arrays over a communication link between the first storage array and the second storage array.

11. The method of claim 9, wherein the step of assigning a unique virtual port identifier (ID) for each physical port is performed by the switch.

12. The method of claim 9, further including the steps of:

coupling a host to the switch;

exchanging data between the host and the virtual array using one of the virtual port IDs assigned to the virtual array.

13. The method of claim 12, wherein the switch comprises ports, each port being coupled to the host, and further comprising the step of generating a zoning table that associates each virtual port ID to one of the ports.

14. The method of claim 13, further comprising the step of limiting communication with the virtual array to the host with a port associated with one of the virtual port ID associated with the virtual array.

15. The method of claim 13, wherein the virtual array spans more than two storage arrays.

16. A storage system comprising:

a host; and

a virtual array spanning a plurality of storage arrays, at least one of the storage arrays having one or more logical units of storage assigned to the virtual array and at least one of the storage arrays having a physical port coupled to the virtual array, the virtual array being assigned a unique virtual port identifier (ID) for each physical port coupled to the virtual array,

wherein the host communicates with the virtual array using a virtual port ID assigned to the virtual array.

17. The system of claim 16, further comprising a communication link between two of the storage arrays sharing the virtual array, each of said storage arrays redirecting an input/output (I/O) request, received by that storage array, over the communication link to the other storage array when the I/O request is addressed to a logical unit of the other storage array.

18. The system of claim 16, further comprising a switch coupled to each host and each storage array, wherein the switch assigns the virtual port IDs to the virtual array.

19. The system of claim 18, wherein the switch comprises:

ports by which the hosts are coupled to the switch; and

a zoning table for associating each virtual port ID with one of the ports.

20. The system of claim 19, wherein each host communicates with the virtual array if that host is coupled to a port associated with one of the virtual port IDs assigned to the virtual array.

21. The system of claim 16, wherein each virtual port ID may be used by one of the hosts to exchange data with the virtual array.

22. The storage system of claim 16, wherein the virtual array spans more than two storage arrays.