Method and apparatus for multiple disk drive access in a multi-processor/multi-disk drive system

• US 6,295,587 B1
• Filed: 09/03/1999
• Issued: 09/25/2001
• Est. Priority Date: 09/03/1999
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Peters, George Garfield, Ryan, Michael Scott, Martin, Brian James
• Primary Examiner(s): Ellis, Kevin L.
• Application Number:
  US09/390,012
• Time in Patent Office: 753 Days
• Field of Search: 711/111, 711/112, 711/114, 711/154, 710/9, 710/131, 710/132
• US Class Current: 711/154
• 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 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

An improved method and apparatus for providing access between the processors and the mass storage devices of a computer system wherein an interprocessor bus interconnects the processors and adapters are connected from the interprocessor bus for communication between the processors and the mass storage devices and the system includes binding utility for communicating with the processors and the adapters to generate pairings between the processors and the adapters. A switch is connected between the adapters and the mass storage devices for connecting each adapter to each mass storage device and a binding mapper operates with the binding utility at each binding of a processor/adapter pair to enumerate the mass storage devices with which a processor/adapter pair is to communicate and determines a mass storage identifier by which the processor identifies the mass storage device. An address mapper references the binding mapper to construct and store an address map having processor set for each mass storage device. Each processor set includes an address map entry for each processor and is indexed by processor number. Each entry contains the mass storage device identifier corresponding to the optimal path of access to the corresponding mass storage device. The address mapper responds to each request for access to a mass storage device by providing the corresponding address map entry and the processor completes the access by directing the request through its paired disk device adapter as determined by the returned address map entry.

Claims

1. For use in a computer system having a first plurality of processors and a second plurality of mass storage devices, an interprocessor bus interconnecting the processors, and a plurality of adapters connected from the interprocessor bus for providing communication between the processors and the mass storage devices, an operating system with a device driver stack, and a binding utility for communicating with the processors and the adapters to generate pairings between the processors and the adapters wherein each processor/adapter pairing is an association of a processor with an adapter, an improved mechanism for providing access between the processors and the mass storage devices, comprising:

a switch connected between the adapters and the mass storage devices for connecting each adapter to each mass storage device,

a binding mapper communicating with the binding utility at each binding of the adapters and the processors for,

at each binding of a processor/adapter pair,

enumerates the connected mass storage devices with which the processor of the processor/adapter pair is to communicate and determining, for each such mass storage device, a mass storage identifier by which the processor identifies the mass storage device, and

an address mapper incorporated into the operating system device driver stack for constructing and storing an address map, wherein

the address map contains a processor set for each mass storage device wherein

each processor set includes an address map entry for each processor in the system, wherein

each processor set is indexed by a processor number and contains the mass storage device identifier corresponding to an optimal path of access to the corresponding mass storage device, and

the address mapper is responsive to a request for access to a mass storage device by a processor, wherein the request includes a processor name, by providing the corresponding address map entry from the processor set corresponding to the requesting processor, wherein

the requesting processor completes the access to the mass storage device by directing the request through the adapter paired with the processor as determined by the returned address map entry.

2. For use in a computer system having a first plurality of processors and a second plurality of mass storage devices, an interprocessor bus interconnecting the processors, and a plurality of adapters connected from the interprocessor bus for providing communication between the processors and the mass storage devices, and a binding utility for communicating with the processors and the adapters to generate pairings between the processors and the adapters wherein each processor/adapter pairing is an association of a processor with an adapter, an improved method for providing access between the processors and the mass storage devices, comprising the steps of:

connecting a switch between the adapters and the mass storage devices for connecting each adapter to each mass storage device, binding the adapters and the processors by operation of the binding utility and, at each binding of the adapters and the processors by the binding utility, and

at each binding of a processor/adapter pair,

enumerating the connected mass storage devices with which the processor of the processor/adapter pair is to communicate and determining, for each such mass storage device, a mass storage identifier by which the processor identifies the mass storage device, and

constructing and storing an address map, wherein

the address map contains a processor set for each mass storage device wherein

each processor set includes an address map entry for each processor in the system, wherein

each processor set is indexed by a processor number and contains the mass storage device identifier corresponding to an optimal path of access to the corresponding mass storage device, and

in response to each request for access to a mass storage device by a processor wherein the request includes a processor name,

providing the corresponding address map entry from the processor set corresponding to the requesting processor, wherein

completing the access to the mass storage device by directing the request through the adapter paired with the requesting processor as determined by the returned address map entry.