Selective correction of data errors

• US 6,701,451 B1
• Filed: 08/11/2000
• Issued: 03/02/2004
• Est. Priority Date: 08/11/2000
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Cohen, Aviram, Kedem, Ishai
• Primary Examiner(s): Beausoliel, Robert
• Assistant Examiner(s): Wilson, Yolanda L
• Application Number:
  US09/637,615
• Time in Patent Office: 1,299 Days
• Field of Search: 714/5, 714/48, 714/6, 714/42, 714/54, 714/723, 714/718, 711/114
• US Class Current: 714/5.1
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: G06F 11/0775 Content or structure details of the error report, e.g. specific table structure, specific error fields
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40

Abstract

A method for scanning a mass-storage device in communication with a global memory includes allocating a scan buffer in the global memory for placement of information descriptive of any errors found during the scan. When a scanning utility identifies a data error on the mass-storage device, it writes structured information descriptive of the error to the scan buffer. This information is available to an error-correction utility. The error-correction utility uses this information to determine, with a minimum of human intervention, which data errors to repair and which to ignore.

Claims

1. A method of scanning a mass-storage device in communication with a global memory, said method comprising

allocating a scan buffer in said global memory;

scanning said mass-storage device;

during said scan of said mass-storage device, detecting a data error in said mass-storage device;

writing, to said scan buffer, information descriptive of said data error, and

including, as part of said information descriptive of said data error, information identifying a mass-storage device from said plurality of mass-storage devices.

2. The method of claim 1 wherein writing to said scan buffer comprises interleaving, within said scan buffer, information descriptive of data errors occurring in different mass-storage devices.

3. The method of claim 1 wherein writing information descriptive of said data error comprises writing an error code indicative of a type of data error.

4. The method of claim 1 wherein writing information descriptive of said data error comprises writing a time stamp indicative of when said data error was recorded in said buffer.

5. The method of claim 1 wherein writing information descriptive of said data error comprises writing an address code indicative of a logical location of said data error in said mass storage medium.

6. The method of claim 1 wherein writing information descriptive of said data error comprises writing a signature indicative of a scanning utility detecting said data error.

7. The method of claim 1 wherein writing information descriptive of said data error comprises writing a repair flag indicative of whether said data error is to be repaired.

8. The method of claim 1 wherein writing information descriptive of said data error comprises writing a status flag indicative of whether said data error has been repaired.

9. A method of repairing a data error in a mass storage system having a global memory in communication with at least one mass-storage device, said method comprising retrieving, from a scan buffer in said global memory, information descriptive of said data error;

implementing a pre-programmed rule for deciding, on the basis of said information descriptive of said data error, whether said data error is to be repaired; and

displaying said information descriptive of said data error to a system operator; and

if said data error is to be repaired, repairing said data error.

10. A data storage system comprising:

a mass-storage device;

a global memory in data communication with said mass-storage device; and

a scan buffer allocated in said global memory, said scan buffer containing information descriptive of data errors in said mass-storage device, said scan buffer including an error entry corresponding to a data error on said mass-storage device.

11. The data storage system of claim 10 wherein said error entry comprises an errorclass field containing information indicative of a type of data error.

12. The data storage system of claim 10 wherein said error entry comprises a statusflag field containing information indicative of whether said data error has been repaired.

13. The data storage system of claim 10 wherein said error entry comprises a repair-flag field containing information indicative of whether said data error is to be repaired.

14. The data storage system of claim 10 wherein said error entry comprises a signature field containing information indicative of a scanning utility detecting said data error.

15. The data storage system of claim 10 wherein said error entry comprises a timestamp field containing information indicative of when said data error was recorded in said buffer.

16. The data storage system of claim 10 wherein said error entry comprises an address field containing information indicative of a logical location of said data error in said mass storage medium.