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

• US 6,530,002 B1
• Filed: 08/01/2001
• Issued: 03/04/2003
• 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: Martin, Brian James, Peters, George Garfield, Ryan, Michael Scott
• Primary Examiner(s): Ellis, Kevin L.
• Application Number:
  US09/920,169
• Time in Patent Office: 580 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. In a computer system having a first plurality of processors, a second plurality of mass storage devices, a third plurality of adapters for providing communication between the processors and the mass storage devices, a binding mechanism for determining relationships between the processors and the adapters and a switch mechanism for establishing communication paths between the adapters and the mass storage devices, a mechanism for providing access between the processors and the mass storage devices, comprising:

a binding mapper communicating with the binding mechanism for determining the mass storage devices of the plurality of mass storage devices with which each processor is to communicate, and

a device driver stack address mapper responsive to the binding mapper for constructing an address map, wherein

the address map contains a processor set for each mass storage device wherein each processor set includes at least one address map entry for each processor that is to communicate with the corresponding mass storage device and each address map entry defines a communication path through an adapter and the switch between a processor and a mass storage device with which the processor is to communicate.

2. The mechanism for providing access between processors and mass storage devices of claim 1, wherein:

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

the requesting processor is responsive to the corresponding address map entry by directing the request through the communication path through an adapter and the switch as determined by the corresponding address map entry.

3. In a computer system having a first plurality of processors, a second plurality of mass storage devices, a third plurality of adapters for providing communication between the processors and the mass storage devices, a binding mechanism for determining relationships between the processors and the adapters and a switch mechanism for establishing communication paths between the adapters and the mass storage devices, a method for providing access between the processors and the mass storage devices, comprising the steps of:

by operation of the binding mechanism, establishing relationships between the processors and the adapters,

at each binding of a processor and adapter, determining by operation of a binding mapper the mass storage devices of the plurality of mass storage devices with which each processor is to communicate, and

constructing an address map, wherein

the address map contains a processor set for each mass storage device wherein each processor set includes at least one address map entry for each processor that is to communicate with the corresponding mass storage device and each address map entry defines a communication path through an adapter and the switch between a processor and a mass storage device with which the processor is to communicate.

4. The mechanism for providing assess between processors and mass storage devices of claim 3, further comprising the steps of:

in response to a request for access to a mass storage device by a processor, providing the corresponding address map entry from the processor set corresponding to the requesting processor, and

in response to the corresponding address map entry, directing the request thought the communication path through an adapter and the switch as determined by the corresponding address map entry.