System, method, and software for a virtual host bus adapter in a storage-area network

• US 7,240,098 B1
• Filed: 05/09/2002
• Issued: 07/03/2007
• Est. Priority Date: 05/09/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Mansee, Mark Thomas
• Primary Examiner(s): Jaroenchonwanit; Bunjob
• Assistant Examiner(s): Refai; Ramsey
• Application Number:
  US10/143,456
• Time in Patent Office: 1,881 Days
• Field of Search: 719321-327, 703/24, 703/25, 703/27, 710/8, 710/63, 710 72- 74, 709/212, 709/250
• US Class Current: 709/212
• 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 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
• CPC Class Codes: H04L 69/322 Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence

Abstract

Accessing some storage-area networks (SANs) requires a client computer to include a special electronic component, known as a host bus adapter (HBA). However, the present inventor recognized that conventional host bus adapters add considerable expense to the cost of accessing the storage-area network. Accordingly, the present inventor devised a host bus adapter that is implemented in software and thus referred to as a “virtual” host bus adapter. One exemplary embodiment of the virtual host bus adapter includes a hardware-emulation module that makes the virtual host bus adapter appear to operating system environments as a conventional host bust adapter with dedicated hardware.

Claims

1. A method comprising:

loading driver software into memory for execution by a local operating system;

establishing a TCP/IP socket connection between the local operating system and a storage router;

inducing the local operating system to falsely recognize the driver software as having associated hardware, and thus to assign a controller number and a DMA memory address to the driver software;

using the established TCP/IP socket connection to request identity of one or more target storage devices accessible via the storage router;

receiving from the storage router data identifying each of a set of target storage devices accessible through the storage router using a world-wide unique name; and

assigning local SCSI device names to each of the identified target storage devices from available names reserved for the driver software as a result of its being recognized as a controller by the local operating system.

2. The method of claim 1, wherein inducing the local operating system to falsely recognize the driver software as having associated hardware, includes at least one of:

issuing a ScsiPortInitialize call;

issuing a scsi_register_module call, or invoking a iSCSI nuscsitcpactlun utility, or adding a device in an sd.conf file.

3. The method of claim 1, wherein the available names reserved for the driver software are based on names present in a non-volatile binding file.

4. A machine readable medium comprising instructions for:

loading driver software into memory for execution by a local operating system;

establishing a TCP/IP socket connection between the local operating system and a storage router;

inducing the local operating system to falsely recognize the driver software as having associated hardware, and thus to assign a controller number and a DMA memory address to the driver software;

using the established TCP/IP socket connection to request identity of one or more target storage devices accessible via the storage router;

receiving from the storage router data identifying each of a set of target storage devices accessible through the storage router using a world-wide unique name; and

assigning local SCSI device names to each of the identified target storage devices from available names reserved for the driver software as a result of its being recognized as a controller by the local operating system.

5. The medium of claim 4, wherein the available names reserved for the driver software are based on names present in a non-volatile binding file.

6. Apparatus comprising:

means for loading driver software into memory for execution by a local operating system;

means for establishing a TCP/IP socket connection between the local operating system and a storage router;

means for inducing the local operating system to falsely recognize the driver software as having associated hardware, and thus to assign a controller number and a DMA memory address to the driver software;

means for using the established TCP/IP socket connection to request identity of one or more target storage devices accessible via the storage router;

means for receiving from the storage router data identifying each of a set of target storage devices accessible through the storage router using a world-wide unique name; and

means for assigning local SCSI device names to each of the identified target storage devices from available names reserved for the driver software as a result of its being recognized as a controller by the local operating system.

7. The apparatus of claim 6, wherein the available names reserved for the driver software are based on names present in a non-volatile binding file.