IIIH
US006269453B1
(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
Corporation—CX01-2/N26.
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
