(12) United States Patent ao) Patent No.: us 6,269,453 Bi
Krantz (45) Date of Patent: Jul. 31,2001
G. A. Gibson, "Redundant disk arrays . . . ", vol. 52/08-b of
dissertation abstract international, pp. 4309, 1991.*
A Case for Redundant Array of Inexpensive Disks (RAID),
David A. Patterson, Garth Gibson, Randy H. Katz, Report
No. UCB/CSD 87/391, Dec, 1987, Computer Science Divi-
sion (EECS), University of California, Berkeley, CA 94720.
A Case for Redundant Arrays of Inexpensive Disks (RAID),
David A. Patterson, Garth Gibson, and Randy H. Katz, ACM
SIGMOD Conference—Jun. 1-3, 1988, Chicago, Illinois.
Two Papers onRAIDs, Peter Chen, Garth Gibson, Randy H.
Katz, David A. Patterson, Martin Schulze, Report No. UCB/
CSD 88/479, Dec, 1988, Computer Science Division
(EECS), University of California, Berkeley, CA 94720.
An Introduction to RAID—Redundant Arrays of Inexpensive
Disks, Peter McLean, Apr. 24, 1991, Digital Equipment
Software and Performance Issues in the Implementation of
a RAID Prototype, Edward K. Lee, Report No. UCB/CSD
90/573, May 1990, Computer Science Division (EECS),
University of California, Berkeley, CA 94720.
A Queuing Analysis of RAID Architectures, Schenze Chen
and Don Towsley, COINS Tech. Report 91-71, Department
of Computer and Information Science, University of Mas-
sachusetts, Amherst, MA 01003.
* cited by examiner
Primary Examiner—Norman M. Wright
(74) Attorney, Agent, or Firm—J. Bradford Leaheey;
William J. Kubida; Hogan & Hartson LLP
In a storage system having a plurality of disks arranged in a RAID array with one of the disks failed, a method of reorganizing the data on the RAID array at the time of failure to prevent both a decrease in performance of the array and reliability of the data and an increase in the cost of operation. Data from the failed disk is regenerated one strip at a time and written onto the original parity chunk for the strip. The resulting fully folded array has the characteristics of a RAID level 0 array. When a replacement disk is inserted into the array the process is reversed to bring the fully folded array back to a fully redundant condition.
3 Claims, 4 Drawing Sheets