Method and apparatus for polling and selecting any paired device in any drawer

• US 6,021,475 A
• Filed: 02/19/1998
• Issued: 02/01/2000
• Est. Priority Date: 12/30/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bui, Thao Bich, Tran, Christina Hien, Nguyen, Tram Thi Mai
• Primary Examiner(s): Chan, Eddie P.
• Assistant Examiner(s): Nguyen, Than
• Application Number:
  US09/026,366
• Time in Patent Office: 712 Days
• Field of Search: 395/309, 395/182.04, 395/182.06, 395/182.07, 395/837, 395/839, 395/838, 711/100, 711/114, 711/156, 711/111, 711/112, 711/161, 711/162
• US Class Current: 711/156
• CPC Class Codes: G06F 11/008 Reliability or availability analysis

Abstract

A device adapter maintains a device polling table in memory that can be dynamically changed in response to disk drive device failures and is updated with each poll so that failed devices can be quickly deleted from the table and alternate device polling mapping can be achieved. A system reconfiguration is not necessary to implement the modifications to the system processing. The device adapter is capable of a greater variety of processing tasks than is conventional, including determining cylinder head position and copying data that otherwise would be performed by a control unit.

Claims

1. A device adapter that provides an interface between a plurality of disk devices each having an I/O controller and a controller of a disk drive subsystem in a computer system, the device adapter comprising:

a device adapter controller that receives requests for disk device status information from the disk drive subsystem controller, polls the disk devices for disk device status information, and receives interrupt signals from the disk devices that require servicing from the disk drive subsystem controller;

a plurality of device electronic switch elements that provide an interface between the device adapter controller and the disk device I/O controllers;

a device address table containing data that represents a physical address for each disk device; and

a polling information table containing data that represents the disk device status information for the disk devices listed in the device address table;

wherein the device adapter controller receives the disk device status information from the disk devices and dynamically changes the device address table and polling information table data for a disk device in response to disk device status information that indicates the disk device has failed.

2. A device adapter as defined in claim 1, wherein the device adapter controller ignores interrupt signals received from any one of the disk devices that has failed.

3. A device adapter as defined in claim 1, wherein the device adapter further includes a buffer memory that receives write data from the disk drive subsystem controller and records the write data into a disk drive device it has designated a primary device and into a disk drive device it has designated a mirror paired device without further intervention from the disk drive subsystem controller.

4. A device adapter as defined in claim 1, wherein the device adapter maintains the device address table and polling information table according to an arrangement of the disk drive devices into a drawer of devices that includes disk drive devices connected to predetermined ones of the device electronic switch elements.

5. A computer system including:

a central processor unit;

a plurality of disk drive devices each having an I/O controller that manages a flow of data into and out of the corresponding disk drive device;

a disk drive subsystem control unit that receives data read and write requests from users connected to the central processor unit;

a device adapter that provides an interface between the disk drive devices and the disk drive subsystem control unit;

a device adapter controller that receives requests for disk drive device status information from the disk drive subsystem control unit and receives interrupt signals from the disk devices drive that require servicing from the disk drive subsystem control unit;

a plurality of device electronic switch elements that provide an interface between the device adapter controller and the disk drive device I/O controllers;

a device address table containing data that represents a physical address for each disk drive device; and

a polling information table containing data that represents the disk drive device status information for the disk drive devices listed in the device address table;

wherein the device adapter controller receives the disk drive device status information from the disk drive devices and dynamically changes the device address table and polling information table data for a disk drive device in response to disk device status information that indicates the disk drive device has failed.

6. A computer system as defined in claim 5, wherein the device adapter controller ignores interrupt signals received from any one of the disk drive devices that has failed.

7. A computer system as defined in claim 5, wherein the device adapter further includes a buffer memory that receives write data from the disk drive subsystem controller and records the write data into a disk drive device it has designated a primary device and into a disk drive device it has designated a mirror paired device without further intervention from the disk drive subsystem control unit.

8. A computer system as defined in claim 5, wherein the device adapter maintains the device address table and polling information table according to an arrangement of the disk drive devices into a drawer of devices that includes disk drive devices connected to predetermined ones of the device electronic switch elements.