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1、图书馆管理系统的实现基于VB图书馆管理系统的设计与实现论文导读:就爱阅读网友为您分享以下“基于VB图书馆管理系统的设计与实现论文”的资讯,希望对您有所帮助,感谢您对92to.com的支持!附录A外文资料VirtualServersServervirtualizationisoneofthoseraretechnologiesthatsoundstoogoodtobetrue,butit’sreal.Itsearliestusewastoconsolidateunderutilizedserverhardwareontoasmallernum
2、berofmachines.Sincethoseearlydays,ithasgrownintoamultipurposesolutionthatenablesgreaterreliability,improvedmanagement,andotherbenefitsthatmakeitanall-but-indispensabletoolforenterprisedatacenter9administrators.Touseanoversimplifieddefinition,avirtualservermimics,usingsoftw
3、arealone,thebehaviorandcapabilitiesofastand-alonecomputer.Thenomenclatureofvirtualizationissimple.Thebottomofthesoftwarestackisoccupiedbyasingleinstanceofanordinaryoperatingsystemthat’sinstalleddirectlyontotheserverhardware.Abovethat,avirtualizationlayerhandlestheredirecti
4、onandemulationthatmakeupthevirtualcomputer.Thecombinationofthesetwolowerlayersisreferredtoasthehost.ThehostprovidesthefullworkingsofafamiliarPCrightdowntoitsBIOSROM,anditcanspawnasmanyindependentPCs—usingvaryinguser-definedconfigurations—asyouchoose.Asarephysicalservers,av
5、irtualPCisuselessuntilyouinstallanoperatingsystemonit.Theoperatingsystemsthatyouinstallonyourvirtualhostsarecalledguests.InstallingaguestOScanbeaseasyasbootingfromtheOS’sinstallationCD.It’sjustlikeinstallinganOSonaPC,and9ingeneral,ifyouwonderhowvirtualizationwillbehave,tha
6、t’stheanswer:JustlikeaPC.Infact,inanall-Windowsenvironment,it’seasytoloseyourplace:AreyoulookingatyourWindowshostOSoratoneofthefourWindowsguestOSesyoujustinstalled?Youmightgetconfused,butyourguestOSesandtheirapplicationsneverdo.EachguestOSbelievesithasthewholemachinetoitse
7、lf.And,inasense,itdoes.Software-basedhardwareOperatingsystemsandapplicationsrunningonvirtualserversdon’thavedirectcontroloverresourcessuchasmemory,harddrives,andnetworkports.Instead,theVMthatsitsbeneaththeOSandapplicationsinterceptsrequestsforinteractionwithhardwareandhand
8、lesthemasitseesfit.Therealmindblowerthatturnsthistechnologyintosomethingclosetomagicistha