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大型机复习题库1)what'smainframe?Mainframessystemsaredesignedforlargeamountsofdatainmanydifferentandinterconnectedways.Mainframeisamachinethatrunsamainframeoperatingsystem.IntheIBMworld,thisoperatingsystemisz/OS,OS/390,MVS/ESA,VM/ESAandVSE/ESA.2)what'stheadvantageofmainframe?Reliability(可靠性),recoverability,redundancy(冗余),safty,connectivity,concurrency3)what'sOS/390?OS/390isanew,integrated(完整的)enterpriseserveroperatingsystemenvironment.Itincorporates(合并)intooneproductaleading-edgeandopencommunicationserver,distributed(分布式的)dataandfileservices,parallelsysplex(系统综合体)support,object-orientedprogramming,DCEandopenapplicationinterfaces.4)what'stheOS390'Selements?DFSMS,SDSF,TSO,ISPF,DITTO,NETVIEW,SDFII,VTAM,JES2,RACFetc...5)what'sthesysplex?SYSPLEXisacollectionofMVSsystemsthatcooperate(合幷),usingcertainhardwareandsoftwareproducts,toprocesswork.6)howmanytypephysicalstoragearethereinmainframe?CentralStorage(MainStorage)ExpandedStorageAuxiliaryStorage7)what'sjes2?Ajobentrysubsystem(JES)isresponsibleformanagingjobsinanOS/390system.8)what'sjobprocessstage?InputConversionExecutionOutputHardcopyPurge9)what'scataloginmainfram?Mastercatalogisthecatalogthatlistsalltheusercatalogs,systemdatasetsandtheirlocations.Usercatalogisthecatalogthatcanbeaccessedandchangedbyusers.Itholdstheuserdatasets.Thereareone,andonlyone,mastercatalog.Thesearchorderofcatalogis:STEPCATinjobJOBCATinjobAliases(别名)inUserCATMastercatalog10)HowmanytypeareThereseveraltypesofDUMP?SYMPTOMDUMPSNAPDUMPSYSDUMPSYSMDUMPSVCDUMPSTAND-ALONEDUMP11)what’sISPF?ISPF(InteractiveSystemProductivityFacility)isPDF(ProgramDevelopmentFacility)'sprerequisite(首先必备的)licensedprogram.ISPFmustbeinstalledeitherbeforeorduringtheinstallationofPDF.12)WhatisJCL?JCLstandsforJobControlLanguage,JCLisasetofcontrolstatementthatprovidethespecificationnecessarytoprocessajob.13)Whatisthedifferencebetweenkeywordandpositionalparameters?Positionalparametersarecharacterized(表現特色)bytheirpositionintheoperand(操作數)fieldinrelationtootherparameters.Keywordparametersarepositionallyindependentwithrespecttoothersoftheirtypeandconsistingofakeywordfollowedbyanequalsignandvariableinformation.14)WhatisaDISP?DISPisakeywordparameterwhichisdefinedontheDDstatementandwhichconsistofthefollowingpositionalsubparameters:DISP=(Status,NormalDisp,AbnormalDisp).TheDISPparameterdescribesthecurrentstatusofthedataset(old,new,ormodified)anddirects(指示)thesystemonthedisposition(部署)ofthedataset(pass,keep,catalog,uncatalog,ordelete)eitherattheendofthesteporifthestepabnormallyterminates(.DISPisalwaysrequiredunlessthedatasetiscreatedanddeletedinthesamestep.15)WhatisDISP=SHR?DISP=SHRpermitsolddatasetstobeshared.SHRisidentical(同样的)toOLDexceptthatseveraljobsmayreadthedatasetconcurrently(并发的)inmultiprogramming(多道程序设计)environments.SHRmustbeusedonlyforinputdatasets;useOLDorMODifdatasetismodified.?SharingdatasetisnecessarybecausepubliclibrarieslikeSYS1.LINKLIBorthesubroutine(子程序)librariesshouldbeavailabletoeveryjobinthesystem.16)WhatisDISP=MOD?DISP=MODmodifiesasequential(顺序的)dataset.Itisaconvenient(方便的)waytoadddatatotheendofsequentialdataset.Ifthedatasetdoesn'texist,thesystemchangesMODtoNEWunlesstheVOLparameterrequestspecificvolume.WhenVOLiscoded,thesystemexpectstofinddatasetonthespecifiedvolumeandterminatesthestepifitcannotfindit.MODistheusualwayofextendeddatasetsintoseveraldirect-access(随机存储)volumes.17)WhatisDISP=PASS?PASSpassesthedatasetontosubsequent(后来的)jobsteps,andeachstepcanusethedatasetonce.ItisapositionalsubparameteroftheDISPwhichcouldonlybespecifiedundernormalterminationaction.Passsavestimebecausethesystemretains(保留)thedatasetlocationandvolumeinformation.18)WhataretheparametersthathavetobecodedonaDDstatementinordertoretrieve(找回)acatalogeddataset?TheminimumparametersneededareDSNandDISP.19)Howdoesthesystemgetinformationabouttheblocksize?DCBinfocomesfrom:-1)Program-FD:BLOCKCONTAINS3RECORDSRECORDCONTAINS100CHARACTERS2)Thelabel-likeatape3)FromtheVTOC-forDasd4)FromtheJCL-DCB=BLKSIZE=nnn.20)WhatisaLabel?LABELisakeywordparameterwhichcanbespecifiedonDDstatementandconsistsofthefollowingsubparameters:LABEL=(RelativeFile#,TypeofLabelProcessing)TheLABELparametertellsthetypeoflabel,therelativefilenumber,andwhetherthedatasetistobeprotectedforinputoroutput.21)WhenshouldbeNLbespecifiedasatypeoflabelprocessing?NLshouldbespecifiedwhenaprogramneedstoprocessunlabeledtapes,NLcanalsobespecifiedwhenthepgmwantstocreateunlabeledtapebecausethesystem'sdefaultaction,incases(万一)whenparameterisnotspecified,willcreateIBMstandardlabel.Nonlabeledtapesareoftenusedforsendingtapestoanotherinstallation.Thatwayyoudon'thavetoworryaboutthetapelabelcorresponding(相应的)tothestandardsattheotherinstallationoraboutaccidentallymatchingthevolumeserial(连续的)numberofanexistingtapeattheinstallation.22)Howdoyoudescribetheinputdatawhichisapartoftheinputjobstream?YoushoulduseeitherDD*orDDData.23)Whatisthedifferencebetween*andData?DD*andDDDATAdescribetheinputdatawhichfollowstheabovementioncards.Iftheinputdatacontainsrecordswitch//incol1and2thenDDDatashouldbeused.24)WhatisthepurposeofSPACEparameter