US 2003/0151837 A1 · Method and apparatus for implementing adaptive reordering of data recovery procedure steps in a disk drive

Abstract

A method and apparatus are provided for implementing adaptive reordering of data recovery procedure (DRP) steps in a direct access storage device (DASD). An initial set of DRP steps is stored. A reorder table is stored during the operation of the DASD. The reorder table includes data recovery data for each data head of successful predefined DRP step numbers. When a DRP process is started, checking for a modified DRP step is performed using the reorder table. Responsive to not identifying the modified DRP step, file parameters for a DRP read operation are set based on the initial set of DRP steps. Responsive to identifying the modified DRP step, file parameters for a DRP read operation are set based on a reordered DRP step that is identified by using the stored successful predefined DRP step numbers in the reorder table. When a successful DRP read operation is identified, the data recovery data in the reorder table are updated. The reordered DRP step is an identified most frequently occurring DRP step number in the reorder table for the current data head. The data recovery data for each data head stored in the reorder table includes a number of total errors, a number of errors above a set threshold, and a reorder flag. The reorder flag is set based upon the number of errors above the set threshold being at least a predefined percentage of the number of total errors. When the reorder flag is set, a reordered DRP step is identified using the stored successful predefined DRP step numbers in the reorder table.

Claims16

Dependent claims

A method for implementing adaptive reordering of data recovery procedure (DRP) steps in a direct access storage device (DASD) comprising the steps of:

storing an initial set of DRP steps;
storing a reorder table during operation of the DASD;
said reorder table including data recovery data for each data head including successful predefined DRP step numbers;
starting a DRP process, checking for a modified DRP step using said reorder table;
responsive to not identifying said modified DRP step, setting file parameters for a DRP read operation based on a DRP step from said initial set of DRP steps;
responsive to identifying said modified DRP step, setting file parameters for a DRP read operation based on a reordered DRP step;
said reordered DRP step identified using said stored successful predefined DRP step numbers in said reorder table;
and
identifying a successful DRP read operation and updating said data recovery data in said reorder table.

6 more elements

Apparatus for implementing adaptive reordering of data recovery procedure (DRP) steps in a direct access storage device (DASD) comprising:

a disk drive controller;
a memory coupled to said disk drive controller for storing an initial set of DRP steps and a reorder table;
said reorder table including data recovery data for each data head;
said disk drive controller for starting a DRP process, and checking for a modified DRP step using said reorder table;
said disk drive controller responsive to not identifying said modified DRP step, for setting file parameters for a DRP read operation based on a DRP step from said initial set of DRP steps;
said disk drive controller responsive to identifying said modified DRP step, for setting file parameters for a DRP read operation based on a reordered DRP step;
said reordered DRP step being identified by using said said reorder table;
and
said disk drive controller for identifying a successful DRP read operation and for updating said data recovery data in said reorder table.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for implementing adaptive reordering of data recovery procedure steps in a disk drive

Life of this patent

Method and apparatus for implementing adaptive reordering of data recovery procedure steps in a disk drive

Life of this patent

Abstract

Claims16