Method and controller for minimizing reads during partial stripe

Details Method and controller for minimizing reads during partial stripe Method and controller for minimizing reads during partial stripe

1994-03-14

1996-04-09

Oberley, Alvin E.

Dynamic information storage or retrieval

Information location or remote operator actuated control

Selective addressing of storage medium

369178, 3642384, 364243, 364248, 364DIG1, 364964, 3649665, 364968, 364DIG2, G11C 1100, G06F 1200, G06F 1310

Patent

active

055069770

ABSTRACT:
A disk controller which minimizes the rad operations required during parity writes of less than a single stripe. The disk array can be generalized as including N+1 disk drives with each stripe including a block on each of the N drives storing data and a block in 1 drive storing parity information. The present invention operates during writes to K blocks of a stripe where K is less than N, i.e., a partial stripe write. If K is greater than (N-1)/2, the N-K unwritten blocks are read in order to compute the new parity information before the actual write take place. If K is less than or equal to (N-1)/2, then the controller only reads the old parity information and the old data in the sectors to be written to compute the new parity. Thus the number of reads required to compute the new parity information is minimized.

REFERENCES:
patent: 4775978 (1988-10-01), Hartness
patent: 5088081 (1992-02-01), Farr
patent: 5124987 (1992-06-01), Milligan et al.
patent: 5148432 (1992-09-01), Gordon et al.
patent: 5155835 (1992-10-01), Belsan
patent: 5166936 (1992-11-01), Ewert et al.
patent: 5191584 (1993-03-01), Anderson
patent: 5206943 (1993-04-01), Callison et al.
patent: 5208813 (1993-05-01), Stallmo
patent: 5210866 (1993-05-01), Milligan et al.
patent: 5253256 (1993-10-01), Oyama et al.
patent: 5263145 (1993-11-01), Brady et al.
Schultz et al, "How Reliable is a RAID", Apr. 1989, pp. 118-123.
Bhargava et al, "Adaptability Experiments in the RAID Distributed Database System", Apr. 1990, pp. 76-85.
Patterson et al, "Introduction to Redundant Arrays of Inexpensive Disks (RAID)", Apr. 1989, pp. 112-117.
Schloss et al, "Highly Redundant Management of Distributed Data", Mar. 1990, pp. 91-95.
"Maximizing Performance in a Striped Disk Array"by Chen et al, IEEE, 1990.

Affiliated with

Also associated with

Rating

Method and controller for minimizing reads during partial stripe does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and controller for minimizing reads during partial stripe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and controller for minimizing reads during partial stripe will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-146274