Method for on-line reorganization of the data on a RAID-4 or RAID-5 array in the absence of one disk and the on-line restoration of a replacement disk

Patent 5390327 Issued on February 14, 1995. Estimated Expiration Date:

June 29, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventors

Assignee

Digital Equipment Corporation

Application

No. 085021 filed on 06/29/1993

US Classes:

714/7, Reconfiguration (e.g., adding a replacement storage component)714/770Disk array

Examiners

Primary: Atkinson, Charles E.

Attorney, Agent or Firm

Cefalo; Albert P., Hudgens; Ronald C., Steubing; Mary M.

International Classes

G06F 011/10
G06F 011/20

Abstract

In a storage system having a plurality of disks arranged in a RAID-4 or RAID-5 array, a method of improving the performance and reliability of the array in the absence of a member. The method re-organizes the array into the equivalent of a higher performance and reliability RAID-0 organization while allowing concurrent high performance application access to the array and includes a deliberate reorganization activity concurrent with application access. The method also restores the RAID-4 or RAID-5 organization subsequent to the failure of a member using a replacement member while continuing to allow concurrent high performance application access to the array. In order to perform this reorganization on-line state information is maintained for each parity block, each data block and the array itself. A recently removed disk may be reinserted using an expedited replacement process.

Other References

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