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CopyrightIBMCorporation2012TrademarksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage1of13LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsCanyoupoint-and-clickonLinuxAbsolutely!
TracyBostJune26,2012WorkingwithLinuxdoesn'tmeanyourworkisrestrictedtocommand-linetools.
True,mostexperiencedLinuxadministratorsusecommand-linetoolsforconvenienceandmoreefficientadministration.
However,theGNOMEprojectprovidessomeexcellenttoolsformanagingaLinuxserverusingagraphicaluserinterface(GUI).
UsingyourMicrosoftWindowsbackgroundexperience,youmightfindthatthesetoolsmakethetransitionlessdramatic.
ViewmorecontentinthisseriesOverviewOtherarticlesinthisseriesViewmorearticlesintheLinuxforWindowsystemsadministratorsseries.
Inthisarticle,learnabouttheseconceptswithLinuxonthedesktop:WorkingwithuserandgroupaccountsManagingfilesandfoldersWorkingwithservicesMonitoringthesystemReviewinglogfilesPrerequisitesTogetthemostfromthearticlesinthisseries,youshouldhaveknowledgeofmanaginguserandgroupaccounts,files,folders,andreviewinglogfilesinaWindowsserverenvironment.
AbasicunderstandingoflogginginandnavigatingaLinuxdesktopenvironmentsuchasLXDE,GNOME,orKDEisexpected.
Additionally,it'sbeneficialtohaveaworkingLinuxcomputertoexploretheconceptsandexamplesinthearticle.
developerWorksibm.
com/developerWorks/LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage2of13WorkingwithuserandgroupaccountsWhenyouconsiderservermanagementfromadesktopenvironment,auserandgroupmanagementtoolisamusthave.
ForthelatestreleaseofGNOME3.
2,thattoolislocatedintheGNOMEControlCenter.
TheGNOMEControlCenterisacentrallocationtomanagevariousaspectsofyourLinuxcomputer—notunliketheWindowsControlPanel.
StillwidelyusedtodayistheGNOMESystemTools(GST).
GSTprovidesusefultoolsforLinuxadministrators,includingatooltomanageuserandgroupaccounts.
SomepopularLinuxdistributionsprovidethesystem-users-configtoolasthedefaultusermanager.
So,nomatteryourLinuxdistribution,youshouldhaveaccesstomanagelocaluseraccountsoutofthebox,usuallyundertheusersandgroupslabel.
LinuxdistributionforthisarticleThedistributionusedforthisarticleisUbuntu10.
0.
4withthedefaultGNOMEdesktopandtheme.
DependinguponyourLinuxdistribution,thescreensanddefaultlocationsofthevarioustoolsdescribedinthisarticlecandifferslightly.
Checkyourdistribution'sdocumentationformorespecifics.
Linuxhasnoregistry.
SotheGUItoolsyouusearejustfront-endtoolstowritedatatoafileonthefilesystem.
Forthetaskofmanagingusersandgroups,youmanagetheunderlying/etc/passwdand/etc/groupfileswiththosetools.
The/etc/passwdfilemaintainsuseraccountinformation,whilethe/etc/groupfilestoresgroupaccountinformation.
Userpasswordsareencryptedinthe/etc/shadowfile,whilegrouppasswordsarestoredinthe/etc/gshadowfile.
TheGNOMEuserandgroupmanagementtoolprovidesastraightforwardinterfaceforaccountmanagement,showninFigure1.
Figure1.
CreatingauserProvidedyouhavetheprivileges,youcancreateandedituserandgroupaccounts.
Inaddition,youcanmanagedetailedaccountsettingssuchaslocationofthehomedirectory,userID,defaultibm.
com/developerWorks/developerWorksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage3of13loginshell,passwordresets,andgroupmembershipassignment.
Standarduserstypicallyhaveaccesstothetoolforpasswordmanagement.
Tocreateanewgroup,clickontheGroupstabandenterthegroupname.
AsshowninFigure2,afteryoucreateagroupyoucanthenmanagethemembershipsimplybyselectingorclearingthecheckboxesnexttousers'names.
Figure2.
CreatingagroupManagingfilesandfoldersInWindows,WindowsExploreristhetoolofchoiceformanytonavigatethefilesystem.
TheGNOMEprojecthasNautilus.
Nautilusisafilemanagerwithastrongdevelopmentteamandwideuserbase.
Ithasbeenindevelopmentsince2001.
IfyouusetheGNOMEdesktop,chancesareNautilusisalreadyinstalled.
IfyouarenotusingGNOME,youcanstilldownloadandinstallNautilus,socheckyourdistribution'sdocumentation.
Oneoftheprimarytasksyouperformwithafilemanagerisnavigatingthefilesystem.
WithNautilus,youcanevenswitchittobrowsermode,whichgivesyoumoreofaWindowsExplorerfeel.
Remember,inLinuxallfoldersaremountedassubfolderstothemainroot(/)directory.
SoifyouhaveremotedrivesmountedtoyourLinuxserver,suchasfromaWindowsoranotherLinuxcomputer,youcannavigatethefilesystemfromtheroot(/)directoryjustasyouwouldadirectorylocatedonthelocalfilesystem,asshowninFigure3.
developerWorksibm.
com/developerWorks/LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage4of13Figure3.
NavigatingthefilesystemNavigatinginNautilusissimilartonavigatinginWindowsExplorer.
Clickonafoldertodrilldownintothesubfolders.
Right-clickonanyfolderorfiletoperformtheusualtasksyou'vecometoexpectwithafilemanager,suchascopy,rename,delete,open,compress,andmanagethepermissions.
Forviewingpreferences,youcansetoptionssuchasdetailedview,listedview,byname,andsoon,asshowninFigure4.
ibm.
com/developerWorks/developerWorksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage5of13Figure4.
ManagingfilepreferencesRead,write,andexecuteWhenyouright-clicktomanagethepermissionsofafolderorfile,youcanvieworchangethepermissions(ifyouraccounthasaccesstodoso).
InNautilus,ifafileorfolderisnotwithinthesecuritypermissionsforyouruseraccount,alockicondisplaysnexttoit.
WithLinux,eachfolderhasthreesetsofpermissions:userowner(u),groupowner(g),andother(o).
Withineachset,youcanassignthebasicpermissionsofread,write,orexecute.
Remembertoassignexecutepermissiontoshellscriptsoranyotherfilesusersneedtoexecute.
UnlikeWindows,inLinuxyouneedtoexplicitlygrantthefileexecutepermissiontothesetofusersthatneedtoperformthataction.
SeeFigure5foranexample.
developerWorksibm.
com/developerWorks/LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage6of13Figure5.
SettingthepermissionsonafileTable1summarizesthebasicpermissionoptionsforatypicalLinuxfile.
IincludeoctalrepresentationbecausemanyLinux-relatedinstallationandsoftwaredocumentsreferencethepermissionsinoctalnotation.
Table1.
LinuxpermissionsPermissionOctalrepresentationReadonly4Writeonly2Executeonly1Readandwrite6Readandexecute5Fullpermission(read,write,andexecute)7WhenyoucreateanewfileusingNautilus,itusestheunderlyingLinuxconfigurationforumask,justlikewhenyoucreateafilefromthecommandline.
Theumaskdeterminesthedefaultpermissions.
MostLinuxdistributionsdefaulttoumask022.
Filesworkfromthe666octal.
Youjustneedtodosomesubtractiontounderstandhowumaskworks.
Ifyoucreateanewfileandtheumaskis022,thefile'sdefaultpermissionsare666-022,or644.
That'stosaytheuserownerhasreadandwritepermission,whilethegroupownerandotherhaveread-onlypermission.
ThesameconceptapplieswhenyoucreatefoldersusingNautilus.
Foldersworkfromthe777octal.
Withthesameumaskof022,ifyoucreateanewfolderitsdefaultpermissionsare777-022,ibm.
com/developerWorks/developerWorksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage7of13or755.
Thismeanstheuserownerhasfullpermission,andthegroupownerandotherhavereadandexecutepermission.
SharingAsinWindowsExplorer,youcaneasilyshareafolderusingNautilus.
Todoso,right-clickonthefolderyouwanttoshare,andselecttheSharingOptionsmenuitem.
Next,selecttheSharethisfoldercheckbox,asshowninFigure6.
Figure6.
SharingafolderAdditionally,youcanselecttheAllowotherstocreateanddeletefilesinthisfoldercheckboxifyouwantotherpeopletobeabletosavedocumentsinthefolder.
Ifyoudo,Nautiluswillaskforconfirmationfromyoutochangethefolderpermissions.
Ifyouhaveusersfromamixedenvironment,youcanselecttheGuestaccesscheckboxtoallowthoseusersaccesstothefolderwithouthavingalocalSambaaccountforauthentication.
UsethisoptionwithcarebecauseitcouldintroduceunnecessarysecurityvulnerabilitiestoyourLinuxserver.
IfyouwanttosharethefolderswithWindowsusersandauthenticatethem,youmustfirstsetupandconfigureSambaonyourLinuxserver.
WorkingwithservicesWiththeGSTinstalled,youcanmanageyourserverservicesandvariousotherdaemons(aLinuxwordforservices)withinthedesktopenvironment,similartousingWindowsservices.
ThistoolisusuallylabeledasStartupPreferences,andyoucanlaunchitfromtheSystemmenubyclickingPreferences.
Todate,theGSTdoesn'tcompletelymanageservicessuchasloginas,reload,restart,andsoon.
ItcangiveyouabasisforunderstandingwhatservicesareinstalledonyourLinuxcomputerandwhetheryouwanttorunparticularservicesuponsystemboot.
developerWorksibm.
com/developerWorks/LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage8of13ThegreenandrediconsshownfortheservicesinFigure7indicatewhethertheservicesareenabledordisabledtorunuponsystemboot.
ThesearesimilartotheWindowsservicesautomaticandmanualoptions.
Aseparateiconrepresentswhethertheservicesarerunning.
Figure7.
ViewingarunningsendmailserviceinGSTMonitoringthesystemAlthoughnotidenticaltotheWindowsTaskManager,GNOMESystemMonitorprovidessimilarfunctionality.
Ifyouwantahigh-levelviewofyourLinuxcomputer'sresourceusage,GNOMESystemMonitorcanprovideaquicksnapshotofthesystem.
Thefourmaintabsformonitoringare:SystemProcessesResourcesFileSystemsTheSystemtabprovidesgeneraloperatingsystemandhardwareinformation(memoryandprocessor),muchliketheSystemdialoginWindowsthatdisplayswhenyouclickPropertiesfromtheWindowManagerdesktopicon.
TheProcessestab(Figure8),displaysallrunningprocesses(andtherearemany!
).
Youcansorttheprocessesbyname,centralprocessingunit(CPU)usage,andsoon.
ibm.
com/developerWorks/developerWorksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage9of13Figure8.
KillingaprocessTheResourcestab(Figure9)issimilartotheWindowsTaskManagerPerformancetab.
ItprovideshistoricalgraphingofCPU,memory/swap,andnetworkbandwidthusage.
Figure9.
MonitoringsystemresourcesdeveloperWorksibm.
com/developerWorks/LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage10of13TheFileSystemstabshowsallmountedfilesystemsandgeneralinformationsuchasmountpointsforvariouspartitions,freespace,totalspace,andsoon.
ReviewinglogfilesTheGNOMESystemLogVieweriscomparabletotheEventViewerinWindows.
Underthehood,Linuxtypicallyusesthesyslog(orrsyslog)mechanismtogeneratelogfilesforvariousapplications,serverservices,andsystemmessages.
Thesefilesusuallyresideinthe/var/logdirectoryontheLinuxfilesystem.
SowhenyoufirstopentheGNOMESystemLogViewer,yourdistributionmightprovideawayforthetooltoautomaticallyreadthevariouslogsinthatdirectory.
Ifnot,orifyouchoosetoaddadditionallogfilesintheviewer,simplyclickFile>Add,andnavigatetothedesiredlogfile.
Table2listsanddescribessomeofthecommonLinuxlogsyoumightwanttomonitorwiththelogviewer.
Table2.
LinuxlogfilesLogfileDescriptionboot.
logHardwaredetection,mounting,andothersystemmessagesuponstartupofthemachinesecureSecurityrelatedmessagesmessagesKernelandothergeneralsystemmessageinformationhttpdWebserverlogsdirectorycontainingaccessanderrorlogsinseparatefilescupsDirectorycontaininglogmessagesrelatedtoprintingcronLogmessagesrelatedtoscheduledjobsXorg.
0.
logLogmessagesrelatedtotheX-Windowserverauth.
logAuthenticationsuccessandfailuressambaDirectoryofaccessanderrorlogsrelatingtotheSambaserverTable2isnotanexhaustivelistofthelogfilesyoucanreadwiththelogviewer.
Evenifyouhavecommercialsoftwareinstalledonyourserver,youcanusethelogviewertoviewthoselogsfilesaslongtheyareintheproperlogformat.
Exploreyour/var/logdirectoryandaddthelogfilesthatareappropriateforyourneeds.
OnethingabouttheGNOMESystemLogViewerthatisconsiderablydifferentfromtheWindowsEventVieweristhatmanyofthelogviewsaredependentuponthesettingsfortheunderlyingsystemconfiguration.
Forexample,thelogsfortheApachewebservercanbeconfiguredtorotatedaily.
Inthatcase,thehttpdaccess.
logonlydisplaysthecurrentday'slogmessages,whiletheolderlogfilesaremovedtoarchives.
Youcanstillconfigurethelogviewertoviewthearchivelogsbyaddingthoseaswell.
Whenyouviewyourlogs,youcaneasilyscrollthroughandreadthevariousmessages.
Sometimesthevolumeofmessagescanmakefindingtheinterestinglogs,suchaserrorsorfatalmessages,muchliketheproverbialsearchfortheneedleinthehaystack.
TheGNOMEibm.
com/developerWorks/developerWorksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage11of13SystemLogViewerprovidesafilterfeaturethatallowsyoutodefinevariousfiltersusingregularexpressionstohighlightorshowonlyspecifiedlogmessages.
Forexample,whiletroubleshootinganemailissueforaparticularuser,youmightwanttofilteranddisplayonlymessagesthatcontainthatuser'semailaddress,asshowninFigure10.
Figure10.
DisplayingonlymessagesbaseduponafilterAnmoretypicalexamplefordailyuseistocreatefilterstohighlighterrormessagesinredwhileusinganothercolor,suchasorange,forwarningmessages.
Figure11demonstratesafilterconfigurationthatdisplaysonlyrootloginattempts.
Figure11.
HighlightinglogmessagesbaseduponafilterWithregularexpressions,youcanreallyuseyourimaginationastheneedarisestohighlightordisplayonlythemessagesyouneed.
developerWorksibm.
com/developerWorks/LinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage12of13ConclusionOtherarticlesinthisseriesViewmorearticlesintheLinuxforWindowsystemsadministratorsseries.
AlthoughLinuxisknownforitsabundantcommand-linetools,youdon'thavetouseitthatway.
Overthelastseveralyears,successfulprojectssuchasGNOMEhavemadetremendousstridesinprovidinggoodqualitydesktoptoolsforLinuxsystemadministration.
IfyouaremovingtoLinuxfromaWindowsenvironment,thesetoolscanprovideamorecomfortabletransitionwhileallowingyoutoeffectivelymanageyourLinuxservers.
ibm.
com/developerWorks/developerWorksLinuxforWindowssystemsadministrators:AdministerLinuxwithGNOMEdesktoptoolsPage13of13RelatedtopicsReadWindows-to-Linuxroadmap:Part3.
IntroductiontoWebmin(ChrisWalden,developerWorks,November2003)tolearnmoreaboutbrowser-basedadministrativetoolsforLinux.
TolearnmoreaboutLinuxlogging,checkoutWindows-to-Linuxroadmap:Part5.
Linuxlogging(ChrisWalden,developerWorks,November2003).
LearnmoreaboutthegeneralfeaturesoftheGSTandperformavarietyofadministrativechores.
ExploretheGNOMESystemLogViewer.
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