资源描述：
《Introduction to the Mainframe》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、01_0131738569_ch01i.qxd12/3/0710:53AMPage1CHAPTER1IntroductiontotheMainframeThemainframeisthebackboneofmanyindustriesthatarethelifebloodoftheglobaleconomy.Moremainframeprocessingpowerisbeingshippednowthanhaseverbeenshipped.Businessesthatrequireunparalleledsecurity,availability,
2、andreliabilityfortheir“betyourbusiness”applicationsdependontheIBMzSeries®mainframe,whichrunsthez/OSoperatingsystemandisprotectedbytheIBMResourceAccessControlFacility(RACF).Inthisbook,weexplainthebasicsofz/OS,focusingonz/OSsecurityandRACF.Thischapterdescribestheevolutionofthemai
3、nframeandthereasonsitistheleadingplatformforreliablecomputing.Italsoexplainshowtousethekeyelementsofz/OS.1.1WhyUseaMainframe?Thisbookintroducessecurityadministratorstotheworldofz/OS.WeexpectthatyoualreadyhaveexperiencewithLinux,UNIX,orWindows.Usingthisprerequisiteknowledge,wete
4、achyouhowtousethemainframeandhowtoconfigureRACF,thesecuritysubsystem.Attheendofeachchapter,welistsourcesforadditionalinformation.Ifyouarethekindofpersonwhowantstogorighttotypingcommandsandseeingresults,skiponovertoSection1.2,“GettingStarted,”tolearnaboutthez/OSTimeSharingOption(
5、TSO)environment.However,werecommendthatyoureadtherestofthissectiontounderstandthemainframedesignphilosophy.Manyofthedifferencesbetweenthemainframeandotheroperat-ingsystemsonlymakesenseifyouunderstandthehistoryandphilosophybehindmainframes.1.1.1ALittleHistoryFewindustrieshavehad
6、therapid,almostexplosivegrowththatwehaveseenintheinformationtechnologyindustry.Thetermcomputeroriginallyreferredtopeoplewhodidmanualcalcula-tions.Theearliestnonhumancomputersweremechanicaldevicesthatperformedmathematical101_0131738569_ch01i.qxd12/3/0710:53AMPage22Chapter1Introd
7、uctiontotheMainframecomputations.Mechanicaldevicesevolvedintovacuumtubedevices,which,inturn,werereplacedbytransistorizedcomputers,whichwerereplacedbyintegratedcircuitdevices.Wheredomainframesfitin?ThemainframesweusetodaydatebacktoApril7,1964,withtheannouncementoftheIBMSystem/360
8、™.System/360wasarevolutionarystepinthedevel-opmentofth
