Integrated storage virtualization and switch system

• US 20060206603A1
• Filed: 04/29/2005
• Published: 09/14/2006
• Est. Priority Date: 03/08/2005
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Kimmel, Jeffrey S., Pawlowski, Brian, Rajan, Vijayan, Ross, Gary
• Granted Patent: US 7,747,836 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• 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: 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

A system integrates an intelligent storage switch with a flexible virtualization system to enable efficient service of file and block protocol data access requests for information stored on the system. A storage operating system executing on a storage system coupled to the switch implements the virtualization system to provide a unified view of storage to clients by logically organizing the information as named files, directories and logical unit numbers. The virtualization system is illustratively embodied as a file system having a write allocator configured to provide a flexible block numbering policy that addresses volume management capabilities, such as storage virtualization, at a finer granularity (e.g., a single block) than that of previous non-flexible storage virtualization schemes. The flexible block numbering policy also yields substantial benefits in terms of increased write efficiency and elimination of storage “hot spots”, as well as a compelling point-in-time read-only data image (snapshot) mechanism.

Claims

1. A system configured to service data access requests for information stored on the system, the system comprising:

one or more storage units configured to serve the information;

a storage appliance having a storage operating system that logically organizes the information as named files and logical unit numbers (luns); and

a storage switch coupled to the storage appliance and storage units, the storage operating system configuring the storage switch with virtualization mappings that translates data access requests received at the storage switch to locations of the information served by the storage units, the storage switch transferring the translated data access requests to one or more of the storage units.

2. The system of claim 1 wherein the storage operating system implements a virtualization system to provide a unified view of storage served by storage units.

3. The system of claim 2 wherein the storage operating system is organized as a multi-protocol engine that provides data paths for clients to access information served by the storage units.

4. The system of claim 3 wherein the storage operating system is further organized as a file manager and a lun manager that cooperate to logically organize the information as named files and luns.

5. The system of claim 4 wherein the storage appliance provides network attached storage (NAS) services through the file manager, while also providing storage area network (SAN) services, including lun emulation, through the lun manager.

6. The system of claim 4 wherein the storage operating system is further organized as a volume manager that provides the virtualization mappings to the storage switch over a switch port of the storage appliance.

7. The system of claim 1 wherein storage switch has a plurality of ports interconnected by a switch fabric that provides a switching function to transfer information traffic among the ports.

8. The system of claim 7 wherein the switch fabric is organized as a crossbar having point-to-point connections between all ports on the switch, the point-to-point connections facilitating transfer of information traffic between two ports independent of the transfer of the traffic among other ports of the switch.

9. The system of claim 8 wherein the ports of the storage switch comprise:

ingress data ports coupled to a computer network and the storage appliance;

one or more control ports coupled to the storage appliance; and

egress storage ports coupled to the storage units and one or more external storage modules.

10. The system of claim 1 wherein each storage unit comprises an intelligent device, such as a filer or a storage appliance.

11. The system of claim 1 wherein each storage unit comprises a disk controller coupled to one or more shelves of storage devices, the storage unit including a storage adapter having input/output (I/O) interface circuitry that couples to the storage devices over an I/O interconnect arrangement.

12. The system of claim 11 wherein the storage devices are disks.

13. The system of claim 11 wherein the I/O interconnect arrangement has a fibre channel serial link topology.

14. The system of claim 1 wherein the virtualization mappings correlate (map) a logical view of the information requested by a client to an intermediate physical view of the information exported by the storage units.

15. The system of claim 14 wherein the logical view of the information comprises LUN identifier (ID) and block number metadata.

16. The system of claim 15 wherein the intermediate physical view of the information comprises LUN ID′

and block number′

metadata.

17. A method for servicing a data access request for information stored on a system, the method comprising the steps of:

receiving the data access request at a data port of a storage switch;

configuring the data port with virtualization mappings provided by a virtualization system of a storage appliance coupled to the storage switch;

steering the data access request from the data port directly to one or more storage ports of the switch in response to the virtualization mappings, each storage port coupled to a storage unit of the system; and

accessing one or more locations of storage devices coupled to the storage unit, as determined by one of the virtualization system and storage unit.

18. The method of claim 17 wherein the step of configuring comprises the steps of:

providing the storage switch with mappings of storage locations specified by the data access request; and

creating a connection through the switch between the data port and each storage unit.

19. The method of claim 17 wherein the step of steering comprises the step of buffering the data access request at the data port until transferred to the storage unit, thereby bypassing the storage appliance.

20. The method of claim 17 wherein the data access request is a block-based protocol data access request.

21. A system configured to service data access requests for information stored on the system, the system comprising:

a switch fabric interconnecting data and storage ports;

one or more storage units coupled to the storage ports and configured to serve the requested information;

a multi-protocol engine coupled to the switch fabric and configured to provide data paths for accessing the requested information; and

a volume manager coupled to the switch fabric and configured to provide virtualization mappings that correlate a logical view of the requested information to an intermediate physical view of the information exported by the storage units.

22. The system of claim 21 further comprising:

a logical unit number (lun) manager coupled to the switch fabric and adapted to provide storage area network (SAN) services for the system; and

a file manager coupled to the switch fabric and configured to provide network attached storage (NAS) services for the system.

23. The system of claim 21 wherein the data access requests are block-based protocol data access requests and wherein each data port has a multi-protocol engine configured to receive the block-based protocol data access requests.

24. The system of claim 21 wherein the data access requests are file-based protocol data access requests and wherein the multi-protocol engine is configured to receive the file-based protocol data access requests.

25. Apparatus adapted to service a data access request for information stored on a system, the apparatus comprising:

means for receiving the data access request at a data port of a storage switch;

means for configuring the data port with virtualization mappings provided by a virtualization system of a storage appliance coupled to the storage switch;

means for steering the data access request from the data port directly to one or more storage ports of the switch in response to the virtualization mappings, each storage port coupled to a storage unit of the system; and

means for accessing one or more locations of storage devices coupled to the storage unit, as determined by one of the virtualization system and storage unit.

26. A computer readable medium containing executable program instructions for servicing a data access request for information stored on a system, the executable program instructions comprising program instructions for:

receiving the data access request at a data port of a storage switch;

configuring the data port with virtualization mappings provided by a virtualization system of a storage appliance coupled to the storage switch;

steering the data access request from the data port directly to one or more storage ports of the switch in response to the virtualization mappings, each storage port coupled to a storage unit of the system; and

accessing one or more locations of storage devices coupled to the storage unit, as determined by one of the virtualization system and storage unit.