AIX Workshop for UNIX Administrators_lvm.ppt

AIXWorkshopforUNIXAdministrators LogicalVolumeManagement ComponentsofAIXStorage FilesDirectoriesFileSystemsLogicalStoragePhysicalStorageLogicalVolumeManager Quorum AIXCert Sys Admin Section6 2 2 VGDA VolumeGroupDescriptionAreaVGdefinationinformation veryimportantcontainsinfoaboutthevolumegroup thelogicalvolumesthatinsideonthevolumegroup andthedisksthatmakeupthevgEachmemberdiskhasatleastonecopy1diskVG 2VGDAsresideonthesamedisk2diskVG 3VGDAs onediskhas2copies anotherhave1copy3diskVG 3VGDAs eachdiskhas1copyAndsoon Youneedatleast51 VGDAtogettheVGonlinewhenquorumisswithedon thedefault Quorum cont VolumeGroup VGDA s VGDA s VGDA s VGDA s Loosedisk badluck Loosedisk 66 VGDAmissing badluck Loosedisk 33 VGDAmissing OK Looseany1disk OK AIXCert Sys Admin Section6 2 2 QuorumonORoff YoushouldconsideruseQuorumornot NormallyturnoffformirroredVGs thatmakesevenhalfofthedisksfailed theVGisstillonline AllmemberdiskmustaccessabletovaryonvgToswitchoffquorumchvg Qnvgname AIXCert Sys Admin Section6 5 VGSA volumeGroupStatusArea VGSA comprisedof127bytes whereeachbitrepresentsoneofthe1016 127x8 physicalpartitions pp thatresideoneachdiskusedinmirrioringasabit masktodeterminewhichPPshavebecomestale VolumeGrouplimits Normalvolumegroups mkvg Numberofdisks Max numberofpartitons disk 1 32512 2 16256 4 8128 8 4064 16 2032 32 1016 mkvg s2 t2 ydatavghdisk2 VolumeGrouplimits Bigvolumegroups mkvg B Numberofdisks Max numberofpartitons disk 1 2 4 130048 8 65024 16 32512 32 16256 64 8128 128 4064 2032 1016 LimitationofLVM LogicalVolumeManager LVMPartofAIXnofeenotoptionalactuallyverygoodManagesdisksandtheirattributesbycommandsthroughdatabaseofconfigurationthroughdevicedriversfeatureslikemirroring RAID allocation AIXCert Sys Admin Section6 WorkingwithLogicalVolumeManager rootvg RootVolumeGroup rootvgCreatedautomaticallywhileinstallingAIXPlacedwithinthisVGAIXfilesInitialpagingandotherLVsUsuallyonlythefirstdiskOrtwotoallowmirroringofrootvgOfteninternaldisksRecommendKeeptoasmallnumberofdisks seemksysblater volumegrouprootvg volumegroupB OtherVG OtherVolumeGroupsOtherVGcreatedbytheSystemAdmin NametypicallyrelatedtotheiruseOptionallyendingin vg VGhasoneormoredisksCanlateraddadisktoaVGCanremovediskfromVG ifempty volumegrouprootvg volumegroupB LVMExample DisowndisksreadytoconnectthemtoanothersystemvaryoffvgexportvgorsmittylvmActivatenewlyattacheddiskscfgmgr findsdisksimportvghdiskN anyoneofthedisksvaryonvg mountsfilesystems VolumeGroups PhysicalVolume LogicalVolume AIXCert Sys Admin Section6 4 LVMHow HowdoestheLVMwork UsesalittledatabaseoffactsaboutallknowdisksaboutcurrentlyconnecteddiskscalledtheODMPlusheaderinformationvolumegroupheadersphysicaldiskheaderlogicalvolumeheaderthisallowsexportvg importvg VolumeGroups PhysicalVolume LogicalVolume AIXCert Sys Admin Section5and6 1 LVMFeatures Striping LogicalVolumesstripingExcellentforI OperformanceIntroducetheriskfordatalostRecommend32K 64Kor128Kstripewidth 4to16timesI Osizemostdatabasesdo4Kor8KI O Striping Mirroring Yes youcancombineStripingandMirroringtogetherbyAIX4 3 3ProvidehighperformanceandhighavailabilityTradeoff eatCPUtimedifficulttoconfigdifficultformaintenanceUseH WRAID0 1instead e g 4 PSSAcard AddaLogicalVolumeLogicalvolumeNAME scratch VOLUMEGROUPnametestvg NumberofLOGICALPARTITIONS 64 PHYSICALVOLUMEnames hdisk1hdisk2hdisk3 LogicalvolumeTYPE jfs POSITIONonphysicalvolumemiddle RANGEofphysicalvolumesminimum MAXIMUMNUMBERofPHYSICALVOLUMES touseforallocationNumberofCOPIESofeachlogical2 partitionMirrorWriteConsistency yes Allocateeachlogicalpartitioncopyyes onaSEPARATEphysicalvolume RELOCATEthelogicalvolumeduringyes reorganization LogicalvolumeLABEL MAXIMUMNUMBERofLOGICALPARTITIONS 512 EnableBADBLOCKrelocation yes SCHEDULINGPOLICYforreading writingparallel logicalpartitioncopiesEnableWRITEVERIFY no FilecontainingALLOCATIONMAP StripeSize 64K CreateLV SMITpanel PTO YES Leaveothersastheirdefaults BasicDetails LVMCommand example1 FindunuseddiskslspvAddthemtoaVGorcreateaVGsmittylvm VG AddVGCheckunusedspaceinVGlsvgCreateaLVsmittylvm LV AddLVCreateaFilesystem JFS smittyjfs Addjfs standard whichVG VolumeGroups PhysicalVolume LogicalVolume LVMCommands example2 MovingLVsmigratepv truefornotstripedLVs migratepv llv02hdisk0hdisk6UsesmitlvmCanmigrateLVonadisktoanotherdiskCanemptywholedisk thenremoveit forsuspectdisks Cann tcrossVGboundaryDiskscanbeaddedandremovedfromaVGextendvgandreducevgUsesmitlvmisrecommended VolumeGroups PhysicalVolume LogicalVolume AIXCert Sys Admin Section6 3 5 6and6 4 2 3 LVMcommands example3 reorgvgthiswillmovephysicalpartitions PP aroundinanattempttogetPPsintherightplace VolumeGroups PhysicalVolume LogicalVolume LVMrootvggoodpractice Smallrootvg 1or2disks formksysbbackup MirrorrootvgforAIXdiskprotectionAdddiskhdisk1chvg QnrootvgForhd1tohd8andhd9varcopytheLVmklvcopyhd 1 2 3 4 5 6 7 8 9var 2hdisk1syncvg vrootvgbosboot ad dev hdisk bootlist mnormalhdisk0hdisk1Ormirrorvg srootvgorumirrorvgrootvghdisk1 VolumeGroups PhysicalVolume LogicalVolume LV2 LV1 LV2 LV1 AIXViewpointonSSARAID5disks SSAdiskscanbeusedJBODorRAID5andchangedlater LVMsoftwarewithinAIX DeviceDriver Adapter LV2 LV1 LV2 LV1 LV2 LV1 LV2 LV1 LV2 LV1 LV2 LV1 LV2 LV1 pdisk1 pdisk4 pdisk3 pdisk2 pdisk5 pdisk8 pdisk7 pdisk6 hdisk6 hdisk9 hdisk8 hdisk7 hdisk22 SSARAID5 UsesSSARAID5diskadapterLimit RAID5ondisksonsameloopononeadapterSequenceSetdiskaspossibleRAIDdisksCreateRAIDdiskfromtheseNowmultiplediskslooklikeonebigdisktoAIXUseasnormalPVConventionally 3 Por7 P SSADiskIdentification DifficulttoworkoutwhichdisksiswhichUse smittydevicesSSADisksSSALogicalDisksIdentifyanSSAdiskChooseadisksFlashdiskidentificationlightShowLogicaltoPhysicalSSADiskRelationshiphdiskX p