Method and System for Bad Block Management in RAID Arrays

• US 20070294570A1
• Filed: 08/25/2006
• Published: 12/20/2007
• Est. Priority Date: 05/04/2006
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Dawkins, William P., Polisetti, Suri B.
• Granted Patent: US 7,721,146 B2
• Time in Patent Office: Days
• US Class Current: 714/6.13
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 2211/103 Hybrid, i.e. RAID systems with parity comprising a mix of RAID types
• CPC Class Codes: G06F 2211/1059 Parity-single bit-RAID5, i.e. RAID 5 implementations
• CPC Class Codes: G11C 29/76 using address translation or modifications

Abstract

A system and method for managing bad blocks that utilizes a remapping pool formed across an array of disks to remap bad blocks formed on individual disks. When a bad block is discovered in a particular disk the bad block is then remapped within the remapping pool and is stored across multiple disks.

Claims

1. An information handling system comprising:

a storage system comprising a plurality of storage disks;

a remapping pool comprising a portion of two or more of the storage disks;

a computing system in communication with the storage system, the computing system having a storage controller associated therewith configured to;

identify a bad block within one of the storage disks; and

remap data to be stored in the bad block to the remapping pool such that the remapped data is stored across two or more of the storage disks.

2. The information handling system of claim 1 wherein the storage system comprises a RAID array.

3. The information handling system of claim 1 wherein the storage controller comprises a RAID controller.

4. The information handling system of claim 3 wherein the RAID controller is embedded within the computing system.

5. The information handling system of claim 3 wherein the RAID controller comprises an external component in communication with the computing system.

6. The information handling system of claim 1 where the storage disks comprise hard drives.

7. The information handling system of claim 1 wherein the storage disks comprise storage media selected from the group consisting of SCSI drives, SAS drives, SATA drives, IDE drives, flash memory drives and solid state memory.

8. The information handling system of claim 1 further comprising one or more storage volumes, wherein each storage volume comprises a portion of each of the storage disks.

9. The information handling system of claim 1 further comprising the storage controller operable to remap the bad block data to the remapping pool using a first selected RAID level.

10. The information handling system of claim 9 further comprising the storage controller operable to map data to at least one storage volume formed in the storage system according to the first selected RAID level.

11. The information handling system of claim 9 further comprising the storage controller operable to map data to at least one storage volume formed in the storage system according to a second selected RAID level.

12. The information handling system of claim 9 wherein the storage controller is operable to detect a disk failure within the plurality of storage disks and to reconstruct the failed portion of the remapping pool in accordance with the first selected RAID level and the remaining portion of the remapping pool.

13. A storage controller for managing bad blocks in a storage system comprising:

a bad block identification utility configured to monitor a plurality of storage disks and identify at least one bad block within one of the plurality of storage disks; and

a remapping utility configured to remap the at least one identified bad block to a remapping pool formed from portions of the plurality of storage disks.

14. The storage controller of claim 13 wherein the remapping utility is configured to remap the at least one identified bad block to the remapping pool using a first selected RAID protocol.

15. The storage controller of claim 13 wherein the plurality of storage disks comprise a RAID array.

16. The storage controller of claim 13 wherein the plurality of storage disks comprise at least one storage media selected from the group consisting of SCSI drives, SAS drives, SATA drives, IDE drives, flash memory drives and solid state memory.

17. The storage controller of claim 13 further comprising:

a disk failure detection module configured to detect a failed disk within the plurality of storage disks, the failed disk having a portion of the remapping pool formed thereon; and

a reconstruction module configured to reconstruct the failed portion of the remapping pool based upon the portions of the remapping pool on the remaining non-failed storage disks.

18. A method for managing bad blocks comprising:

forming a remapping pool across a plurality of storage disks;

identifying a bad block with one of the plurality of storage disks;

remapping data to be stored in the bad block to the remapping pool.

19. The method of claim 18 further comprising:

detecting the failure of one of the plurality of storage disks containing a portion of the remapping pool; and

reconstructing the failed portion of the remapping pool using the remaining portions of the remapping pool stored on the remaining non-failed disks.

20. The method of claim 18 comprising remapping the bad block data to the remapping pool using a first selected RAID protocol.