Excavating
Patent
1992-12-07
1998-10-06
Lee, Thomas C.
Excavating
395839, 395441, 371 492, G06F 700, G06F 716
Patent
active
058191097
ABSTRACT:
The present invention is a method of writing data to a storage system using a redundant array of independent/inexpensive disks ("RAID") organization that eliminates the write hole problem of regenerating undetected corrupt data. The invention also overcomes the need for system overhead to synchronize data writes to logical block numbers that map to the same parity block. A log is constructed and used for storing information relating to requested updates or write operations to the data blocks in the multiple disk array. A separate entry is made in the log for each parity block that must be updated as a result of the write operation. Each log entry contains the addresses of the logical block numbers to which data must be written for that operation. After the new data is written to data blocks in the RAID array, a background scrubber operation sequentially reads the next available entry in the log and performs a parity calculation to determine the parity resulting from the write operation. The new parity information is written to the corresponding parity block and the log entry is deleted by the scrubber operation to indicate that the parity block corresponds to the data it represents. In addition, if a system failure occurs during a data write or after the data write but before the associated parity block is written, the original data can be accurately reconstructed using the remaining data blocks and the original parity information that remains in the parity block.
REFERENCES:
patent: 4092732 (1978-05-01), Ouchi
patent: 4434487 (1984-02-01), Rubinson et al.
patent: 4608661 (1986-08-01), Sasaki
patent: 4775978 (1988-10-01), Hartness
patent: 4914656 (1990-04-01), Dunphy, Jr. et al.
patent: 4953122 (1990-08-01), Williams
patent: 4989205 (1991-01-01), Dunphy et al.
patent: 4989206 (1991-01-01), Dunphy et al.
patent: 5072378 (1991-12-01), Manka
patent: 5208813 (1993-05-01), Stallmo
patent: 5257391 (1993-10-01), Dulae et al.
patent: 5263145 (1993-11-01), Brady et al.
patent: 5375128 (1994-12-01), Menon et al.
patent: 5390302 (1995-02-01), Johnson et al.
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 Division (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 on RAIDs, 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 Massachusetts, Amherst, MA 01003.
The Digital Guide to RAID Storage Technology, 1992, Digital Equipment Corporation.
Digital Equipment Corporation
Fisher Arthur W.
Hudgens Ronald C.
Krick Rehana P.
Lee Thomas C.
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