摘要
LargeHighEnergyandNuclearPhysics(HENP)databasesarecommonlystoredonrobotictapesystemsbecauseofcostconsiderations.Later,selectedsubsetsofthedataarecachedintodiskcachesforanalysisordatamining.Becauseoftherelativelylongtimetomount,seek,andreadatape,itisimportanttominimizethenumberoftimesthatdataiscachedintodisk.Havingtoolittlediskcachewillforcefilestoberemovedfromdiskprematurely,thusreducingthepotentialoftheirsharingwithotherusers.Similarly,havingtoofewtapedriveswillnotmakegooduseofalargediskcache,asthethroughputfromthetapesystemwillformthebottleneck.Balancingthetapeanddiskresourcesisdependentonthepatternsoftherequeststothedata.Inthispaper,wedescribeasimulationthatcharacterizessuchasystemintermsofthersourcesandtherequestpatterns.Welearnfromthesimulationwhichparametersaffecttheperformanceofthesystemthemost.Wealsoobservefromthesimulationthat,thereisapointbeyondwhichitisnotworthinvestinginadditionalresourcesasthebenefitistoomarginal.Wecallthispointthe"point-of-no-benefit"(orPNB),andshowthatusingthisconceptwecanmoreeasilydiscovertherelationshipofvariousparameterstotheperformanceofthesystem.
出版日期
2001年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
