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Author Smith, Alan Jay
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Language English
Subject Keyword Memory hierarchies ♦ Mass storage ♦ Paging ♦ File migration ♦ Replacement algorithm
Abstract The steady increase in the power and complexity of modern computer systems has encouraged the implementation of automatic file migration systems which move files dynamically between mass storage devices and disk in response to user reference patterns. Using information describing 13 months of user disk data set file references, we develop and evaluate (replacement) algorithms for the selection of files to be moved from disk to mass storage. Our approach is general and demonstrates a general methodology for this type of problem. We find that algorithms based on both the file size and the time since the file was last used work well. The best realizable algorithms tested condition on the empirical distribution of the times between file references. Acceptable results are also obtained by selecting for replacement that file whose size times time to most recent reference is maximal. Comparisons are made with a number of standard algorithms developed for paging, such as Working Set, VMIN, and GOPT. Sufficient information (parameter values, fitted equations) is provided so that our algorithms may be easily implemented on other systems.
Description Affiliation: Univ. of California, Berkeley, Berkeley (Smith, Alan Jay)
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2005-08-01
Publisher Place New York
Journal Communications of the ACM (CACM)
Volume Number 24
Issue Number 8
Page Count 12
Starting Page 521
Ending Page 532


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Source: ACM Digital Library