Analytic treatment of the reliability and performance of mirrored disk subsystems

TitleAnalytic treatment of the reliability and performance of mirrored disk subsystems
Publication TypeJournal Article
Year of Publication1993
AuthorsR Geist, and K Trivedi
JournalDigest of Papers Ftcs (Fault Tolerant Computing Symposium)
Start Page442
Pagination442 - 450
Date Published12/1993
Abstract

An analytic model is developed for predicting the performance and reliability of mirrored disk subsystems. The model includes Markovian dependencies in the request stream, read and write traffic, unit failures, and individual request failures necessitating retries. A workload model is synthesized from measurements and used as example input. Statistical tests verify the Markovian nature of the request stream. The mirrored system is seen to offer substantial enhancement to both system reliability and performance. Server-selection, i.e., which drive to use to serve a read request, is also considered. The standard mirror policy, `serve closest', is seen to be sub-optimal. A mechanism for optimal selection is suggested.

Short TitleDigest of Papers Ftcs (Fault Tolerant Computing Symposium)