Hard disk drive background scrub methodology

Abstract

A system, method, and computer program product for recovering from data errors. In a SCSI hard drive system, when a unrecoverable data error condition is encountered, the logical block address is reassigned using information provided by the data scrubbing functionality of the SCSI hard drive.

1 . In a computer configuration having a host operating system and a plurality of drives included in a RAID Array, a method for correcting unrecoverable data errors comprising the steps of:
 enabling all of the drives that are defined as a part of a RAID array to perform a background scrubbing operation during a drive idle time;   generating an error notification when an unrecoverable data error is encountered during said scrubbing operation;   communicating said error notification from a selected drive to said host system; and   operating said host system in response to said error notification to correct said unrecoverable data error using data from a redundant drive included in said RAID Array.   
     
     
         2 . The method of  claim 1 , wherein said step of communicating said error notification comprises:
 logging information pertaining to said unrecoverable data error onto a log page associated with said selected drive; and   periodically operating a central processor unit (CPU) associated with said host operating system to poll said selected drive by reading said information on said log page.   
     
     
         3 . The method of  claim 2 , wherein:
 said information logged onto said log page comprises the time of entry, type of data error and logical block address (LBA) of said data error.   
     
     
         4 . The method of  claim 3 , wherein:
 said correction of said unrecoverable data error comprises sending a command from said CPU to said selected drive to reassign said LBA.   
     
     
         5 . The method of  claim 4 , wherein:
 said correction of said unrecoverable data error further comprises writing correct data from said redundant drive to said reassigned LBA.   
     
     
         6 . The method of  claim 5 , wherein:
 each of said drives comprises an SCSI hard drive.   
     
     
         7 . The method of  claim 1 , wherein said step of communicating said error notification comprises:
 returning a Check Condition Status request from said selected drive to said host system, in response to the next command sent to said selected drive from said host system.   
     
     
         8 . The method of  claim 7 , wherein:
 said host system responds to said Check Condition Status request by sending a Request Sense command to said selected drive, whereupon said selected drive returns a set of Sense Data associated with said unrecoverable data error to said host system.   
     
     
         9 . The method of  claim 8 , wherein:
 said Sense Data includes the LBA of said unrecoverable data error.   
     
     
         10 . The method of  claim 9 , wherein:
 said correction of said unrecoverable data error comprises sending a command from a CPU associated with said host system to said selected drive to reassign said LBA.   
     
     
         11 . The method of  claim 10 , wherein:
 said correction of said unrecoverable data error further comprises writing correct data from said redundant drive to said reassigned LBA.   
     
     
         12 . The method of  claim 11 , wherein:
 each of said drives comprises an SCSI hard drive.   
     
     
         13 . A computer system comprising:
 a processor associated with a host operating system;   a plurality of drives included in a RAID array connected to said host operating system; and   a computer readable medium connected to the processor, said computer readable medium including processor instructions configured to be read by said processor and to thereby cause said processor to:   enabling all of the drives that are defined as a part of a RAID array to perform a background scrubbing operation during a drive idle time;   generate an error notification when an unrecoverable data error is encountered during said scrubbing operation;   communicate said error notification from a selected drive to said host system; and   operate said host system in response to said error notification to correct said unrecoverable data error using data from a redundant drive included in said RAID array.   
     
     
         14 . The system of  claim 13 , wherein communication of said error notification comprises:
 logging information pertaining to said unrecoverable data error onto a log page associated with said selected drive; and   periodically operating said processor to poll said selected drive by reading said information on said log page.   
     
     
         15 . The system of  claim 14 , wherein:
 said information logged onto said log page comprises the time of entry, type of data error and logical block address (LBA) of said data error.   
     
     
         16 . The system of  claim 15 , wherein:
 said correction of said unrecoverable data error comprises sending a command from said processor to said selected drive to reassign said LBA.   
     
     
         17 . The system of  claim 16 , wherein:
 said correction of said unrecoverable data error further comprises writing correct data from said redundant drive to said reassigned LBA.   
     
     
         18 . The system of  claim 13 , wherein communication of said error notification comprises:
 returning a Check Condition Status request from said selected drive to said host system, in response to the next command sent to said selected drive from said host system.   
     
     
         19 . The system of  claim 18 , wherein:
 said host system responds to said Check Condition Status request by sending a Request Sense command to said selected drive, whereupon said selected drive returns a set of Sense Data associated with said unrecoverable data error to said host system.   
     
     
         20 . The system of  claim 19 , wherein:
 said Sense Data includes the LBA of said unrecoverable data error.   
     
     
         21 . The system of  claim 20 , wherein:
 said correction of said unrecoverable data error comprises sending a command from said processor associated with said host system to said selected drive to reassign said LEA.   
     
     
         22 . The system of  claim 21 , wherein:
 said correction of said unrecoverable data error further comprises writing correct data from said redundant drive to said reassigned LBA.   
     
     
         23 . In a computer configuration having a host operating system and a plurality of drives included in a RAID Array, a computer program product for correcting unrecoverable data errors comprising:
 first instructions for enabling all of the drives that are defined as a part of a RAID array to perform a background scrubbing operation during a drive idle time;   second instructions for generating an error notification when an unrecoverable data error is encountered during said scrubbing operation;   third instructions for communicating said error notification from a selected drive to said host system; and   fourth instructions for operating said host system in response to said error notification to correct said unrecoverable data error using data from a redundant drive included in said RAID Array.   
     
     
         24 . The product of  claim 23 , wherein said communication of said error notification comprises:
 logging information pertaining to said unrecoverable data error onto a log page associated with said selected drive; and   periodically operating a central processor unit (CPU) associated with said host operating system to poll said selected drive by reading said information on said log page.   
     
     
         25 . The product of  claim 24 , wherein:
 said information logged onto said log page comprises the time of entry, type of data error and logical block address (LBA) of said data error.   
     
     
         26 . The product of  claim 25 , wherein:
 said correction of said unrecoverable data error comprises sending a command from said CPU to said selected drive to reassign said LBA.   
     
     
         27 . The product of  claim 26 , wherein:
 said correction of said unrecoverable data error further comprises writing correct data from said redundant drive to said reassigned LBA.   
     
     
         28 . The product of  claim 23 , wherein said communication of said error notification comprises:
 returning a Check Condition Status request from said selected drive to said host system, in response to the next command sent to said selected drive from said host system.   
     
     
         29 . The product of  claim 28 , wherein:
 said host system responds to said Check Condition Status request by sending a Request Sense command to said selected drive, whereupon said selected drive returns a set of Sense Data associated with said unrecoverable data error to said host system.   
     
     
         30 . The product of  claim 29 , wherein:
 said Sense Data includes the LBA of said unrecoverable data error.   
     
     
         31 . The product of  claim 30 , wherein:
 said correction of said unrecoverable data error comprises sending a command from a CPU associated with said host system to said selected drive to reassign said LBA.   
     
     
         32 . The product of  claim 31 , wherein:
 said correction of said unrecoverable data error further comprises writing correct data from said redundant drive to said reassigned LBA.