By Topic

Mirrored Disk Organization Reliability Analysis

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Thomasian, A. ; Dept. of Comput. Sci., New Jersey Inst. of Technol., Newark, NJ ; Blaum, M.

Disk mirroring or RAID level 1 (RAID1) is a popular paradigm to achieve fault tolerance and a higher disk access bandwidth for read requests. We consider four RAID1 organizations: basic mirroring, group rotate declustering, interleaved declustering, and chained declustering, where the last three organizations attain a more balanced load than basic mirroring when disk failures occur. We first obtain the number of configurations, A(n, i), which do not result in data loss when i out of n disks have failed. The probability of no data loss in this case is A(n, i)/matrix of(n, i). The reliability of each RAID1 organization is the summation over 1 les i les n/2 of A(n, i)rn-i (1 - r) i, where r denotes the reliability of each disk. A closed-form expression for A(n, i) is obtained easily for the first three organizations. We present a relatively simple derivation of the expression for A(n, i) for the chained declustering method, which includes a correctness proof. We also discuss the routing of read requests to balance disk loads, especially when there are disk failures, to maximize the attainable throughput

Published in:

Computers, IEEE Transactions on  (Volume:55 ,  Issue: 12 )