Beforeusingscriptcommandstomanagea storagesubsystem,youshouldbefamiliarwith theseitems: v Controllers v Diskdrives v Hotspares v Arrays v Logicaldrives v RAIDtechnology v Hosts v Hostgroups
v Hostbusadapter(HBA) hostports v Logicalunitnumbers(LUNs)
Configuringa RAIDstoragesubsystemrequirescautionandplanningtomakesurethatyoudefinethe correctRAIDlevelandconfigurationforyourstoragesubsystem.Youconfigurea storagesubsystemto createlogicaldrives, whichare addressablebythehosts,fromacollection ofdiskdrives.Thecommands describedinthischapterhelpyoutosetupandrunaRAID storagesubsystem.Additionalcommands arealsoavailable toprovideyouwith morecontroland flexibility.
Note: Manyofthesecommandsrequire athoroughunderstandingofthefirmware aswell asan understandingofthenetworkcomponentsthatneedtobe mapped.Use theCLIcommandsandthe scriptcommandswithcaution.
Thesectionsinthis chaptershowsome,butnotall,oftheCLIcommandsand thescriptcommands.The commandsinthischaptershowhow youcanusethecommandstoconfigurea storagesubsystem.These presentationsdonotdescribeallpossibleusageandsyntax forthecommands.(For completedefinitions ofthecommands,includingsyntax,parameters,and usagenotes,seeChapter3,“Script Commands,”on page19.
Thischaptercontainsexamples ofCLIcommandusage andscriptcommandusage.Thecommandsyntax thatisusedintheexamplesisforahost runninga Microsoftoperatingsystem.Aspart oftheexamples, thecompleteC:\promptand theDOS pathforthecommandsare shown.Dependingonyouroperating system,thepromptand pathconstructwillvary.
Formostcommands,thesyntax isthesameforallWindows operatingsystemsand UNIXoperating systems,aswellasfora scriptfile.Windows operatingsystems,however,havean additionalrequirement whenenteringnamesinacommand. OnWindows operatingsystems,youmust enclosethename
betweentwobackslashes(\\)inadditiontootherdelimiters.For example,thefollowingnameisused inacommandrunningundera Windowsoperatingsystem:
[\”Engineering\”]
Fora UNIXoperatingsystem,andwhenusedinascriptfile,thenameappears asfollows:
Configuration
Concepts
Thefollowingfigureshowsa hostusingacomputersystem[3],and showsthestoragesubsystemwitha controllermodule[1]and twodriveexpansionenclosures[2]. Thestoragesubsystemhasat leastone controlleranddiskdrives.Thedisk drivesaregrouped togethertoforma logicalstructure.Thestorage subsystemisphysicallyplacedina cabinetasshownontheleftinthefigure.
Whenyouconfigureastorage subsystem,youallocatepartsofthislogicalstructureforusebyone or moreofthehoststhatare attachedtothestoragesubsystem.Eachdiskdriveanddriveexpansion enclosureisnumberedtoallowthestoragetobeorganized intoarraysand logicaldrives.This
organizationhelpstoprovidestoragecapacityanddataprotectionsothatthehosts cansafelystoreand retrievedatafromthestorage subsystem.
Thissection definesthephysicalcomponentsand thelogicalcomponentsthatarerequiredtoorganize andconfigurea storagesubsystem.Thissectionalso describeshowthecomponentsrelatetoeachother.
Controllers
Allstoragesubsystems haveoneor twocontrollers.Thecontrollers arecircuit-boardassembliesthat managedataandcommunicationbetweenthehostsandthestoragesubsystem.Thecontrollermanages thedataflowbetweenthehosts andthediskdrives,keepingtrackofthelogicaladdressofwherethe dataresides.Ingeneral,eachcontrollerhasaprocessor forperformingcontroloperations,NVSRAMfor storingthefirmwarecode thatoperates thestorage subsystem,and thebusesalongwhichthedataflows. Thecontrollersarelocatedina controllermodule,whichprovides twopositions forcontrollers:slotA andslotB.Thescriptcommandsidentifyeachcontrollerbytheslotinwhichthecontrollerisinstalled.If astorage subsystemhasonlyonecontroller,thecontrollermustbe inslotA.Controllers areidentifiedby usingmodelnumbers.
ControllermodelsDS4400and DS4500useminihubs;twoconnectedtoeachcontroller.Whenviewed fromtherearofthecontrollermodule,thehost-sideminihubsarenumbered fromleft-to-righta1,b1,a2, b2.Thescriptcommandsidentifythehostchannelsbyusingthese identifiers.Minihubsalsosupported thedrive-side,whereeachminihubrepresentsa singlechanneltothediskdrives. Whenviewedfromthe rearofthecontrollermodule,thedisk driveminihubsarenumberedfromleftto right4,3,2,1. The scriptcommandsusethese numberstoidentifythediskdrivechannels.
Controllersmanagetheinterfacebyusingthecontrollerfirmwaretotransmitandreceivecommands betweenthehosts andthediskdrives.Hostbusadaptersfacilitatethecommunicationthroughwhatever interfaceisselected.Typically,twohostbusadapters andtwopathsareusedtooptimizeredundancy. Thesecontrollermodules andcontrollermodulesincorporate allhostconnectionsandexpansiondrawer connectionsintoeachcontroller.Thehostportsmust beidentified inyourcommandstatementstolet youcompletetheirnetworkconfigurations.
Themorerecentcontrollers donotuseminihubs.Thesecontrollers havehost portsthatareintegrated intothecontrollercircuitboardsorauxiliarycircuitboardsthataredirectlyconnectedtothecontroller circuitboards.
Thefollowingtableliststhecontrollermodulesthatdonotuseminihubs,thetype ofhostport,and the numberofhostports.
Table10.HostPortsandtheTypeofHostInterfacesonControllerModules
Model AvailableHostPorts TypeofHostInterface
DS3200controllermodule(withoutoptional SASexpansioncard)
1 SAS
DS3200controllermodule(withoptional SASexpansioncard)
3 SAS
DS3300controllermodule 2 iSCSI
DS3400controllermodule 2 FibreChannel
DS4100,DS4200,andDS4300 2 FibreChannel
DS4700(Model70)controllermodule 2 FibreChannel DS4700(Model72)controllermodule 4 FibreChannel
DS4400,DS4500,andDS4800 4 FibreChannel
TheDS4800(Models82,84,88)-seriescontrollermodulehasfourhostportsandfourchannelports on eachcontroller.
TheDS3200controllermodulehasthreehostports [1][2],whicharenumbered fromlefttoright:host port1,hostport2,andhost port3 asshowninthefollowingfigure:
TheDS3300and DS3400controllermoduleshavetwohostports[1]oneachcontroller,whichare numberedfromleft toright:host port1 andhostport2 asshowninthefollowingfigure:
ThehostportsontheDS4200andDS4700 (Model72)controllermodulearenumberedfromleft-to-right oncontrollerBasCh1,Ch2, Ch3,andCh 4.ControllerA, whichisinstalledupside-downinthe enclosure,isnumbered fromright-to-leftinthesamesequence, asshown inthefollowingfigure:
Figure2.DS3200HostPorts
Figure3.DS3400HostPorts
d s4 7 _ h o st _p o rts
A
B
1
2
3
4
1
2
3 4
ThecontrollerintheDS4800controllermodulecanhaveuptofourhostchannelswithoneportforeach channel;uptotwodrivechannelswithtwoportsperchannel(foratotaloffourdriveports);and upto twoEthernetports.IntheDS4800 (Models82,84,88)controllermodule,thecontrollersarestackedone abovetheother. ThetopcontrollerisA.ThebottomcontrollerisB.
ForcontrollerA,thehostchannelidentifiersarea1,a2,a3,and a4(youwillneedthisreferenceforthe CLIcommandsand thescriptcommands).On thecontroller,thehostbusadapter(HBA)hostportsare labeled1,2,3,and 4.ForcontrollerB,thehostchannelidentifiersareb1,b2,b3,andb4.
Onthecontrollers,theHBAhostports arelabeled1,2,3,and 4,asshowninthefollowingfigure:
ControllerAhasdrive channels1and2. Driveportslabeled3 and4 connectto drivechannel1.Drive portslabeled1and 2connecttoDrive Channel2. ControllerBhasdrivechannels3 and4.Drive ports labeled1and2 connecttodrivechannel3.Driveports labeled3and4 connecttodrivechannel4.Each Ethernetportona controllercanhavea uniqueIPaddress;however,bothEthernetports sharethesame gatewayIPaddress,subnetmask,andremote loginsettings.
Disk
Drives
Thediskdrivesprovidetheactualstorageofthedatathatissenttothestorage subsystem.Thedisk drivesaremounted inaexpansiondrawer.Theexpansiondrawerisanenclosurethat,inadditiontothe diskdrives,containspowersupplies,fans, environmentalcards,andothersupportingcomponents. Diskdrives arelocatedinastorage subsystembyenclosureIDandslotID.Enclosure IDvaluesare0 to 99.Inolderenclosures,enclosureIDvaluesareset duringinstallationbyswitchesontherearofthe enclosures.Innewerenclosures, enclosureIDvaluesareset automaticallywhen thepowerisapplied. TheslotIDisthediskdrivepositionintheexpansiondrawer.SlotIDvaluesrangefrom1 to16.A expansiondrawercancontaineither10,12,14,or16diskdrives.Thetotalnumberofdiskdrives ina storagesubsystemdependsonthemodelofthecontrollerandthetype ofexpansiondrawer.
A
B
ds48_host_ports
4 3 2 1
1 2 3 4
Note: Amaximumofsevenexpansiondrawerscanbe ona channelwhenmixing14-slotexpansion drawersand 16-slotexpansiondrawers.
Thefollowingtablelists,bycontrollernumber andexpansiondrawercapacity,themaximum numberof diskdrivesina storagesubsystem.
Table11.MaximumNumberofDiskDrives
ControllerModel 10-DiskDrive ExpansionDrawer 12-DiskDrive ExpansionDrawer 14-DiskDrive ExpansionDrawer 16-DiskDrive ExpansionDrawer DS3200 48 DS3300 48 DS3400 48 DS4300–SCU 14 DS4300 112 100-1101 DS4200 100-1101 112 DS4700 112 112 DS4400 220 224 DS4500 220 224 224 DS4800 224 224 DS5100 224 224 DS5300 224 224 1
Note: TherearemaximumlimitstothenumberofFibreChannelharddrivesthatyoucanconfigureinredundant drivelooppairs.Themaximumnumberofdrivesdictatesafixednumberofsupported14-diskand16-diskdrive enclosurecombinations.Formoreinformation,pleaserefertoChapter1oftheDS4000HardDriveandStorage ExpansionEnclosureInstallationandMigrationGuide.
Hot
Spares
Ahotspareisadiskdrivethatacts asa standbyintheeventthata diskdrivecontainingdatafails.The hotspareisadiskdrivethathasnotbeenassignedtoaparticulararrayand, assuch, canbeusedinany array.Youcanusethehotsparefeaturewith RAID1,RAID3, RAID5,orRAID6.
Note: Some DS3000andDS4000 controllerfirmwareversionsdo notsupport RAID6.(Firmwareversion 7.3x.xx.xxfortheDS5000 supportsRAID 6.)Formoreinformation,seetheDS3000 andDS4000 controller firmwarereadmefilesortheinteroperabilitymatrices.
Ifadiskdriveina arrayfails,thecontrollersautomaticallyreplacethefailed diskdrivewitha hotspare. Thecontrollersuseredundancydatatoreconstructthedatafromthefailed diskdriveontothehotspare. Tobemosteffective,thediskdrivethatyouassignasahotsparemusthaveacapacityequalto or greaterthanthecapacityofthelargestdiskdriveinthestoragesubsystem.Thehotsparemustbe the sametypeofdisk driveasthediskdrivethatfailed (forexample,aSerialAdvancedTechnology Attachment[SATA]hotsparecannotreplacea FibreChannelhotspare).
Youcanassigndiskdrivesto actashotsparesmanuallyorhavethescriptcommandsautomatically assignhotspares.Ifyoumanuallyassignadiskdrivetobe ahotspare,youmustidentifythediskdrive byenclosure IDand slotID. Whenyouletthescriptcommandsautomaticallyassignhotspares,you mustenterthenumberofhotsparesthatyouwantinthestoragesubsystem.Themaximumnumberof hotsparediskdrives perstoragesubsystemis15.
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Arrays
Aarrayisa setofdiskdrives thatarelogicallygrouped togetherbythecontrollers inastorage subsystem.Afteryoucreateaarray, youcancreateoneormorelogicaldrivesinthearray.Aarrayis identifiedbyasequencenumberthatisdefinedbythecontrollerfirmwarewhenyoucreatedthearray. Tocreateaarray,youmustdefinethecapacityand theRAID level.
Capacityisthesizeofthearray.Capacityisdeterminedbythenumberofdisk drivesthatyouassignto thearray.Youcanuseonlyunassigneddiskdrivestocreatea array.(Inthisprogrammingguide,the storagespaceonunassigneddiskdrives constitutestheunconfiguredcapacityofa storagesubsystem.)
Freecapacityisacontiguousregionofunassignedcapacityin adesignatedarray.Beforeyoucreateanew logicaldriveina array,youneedtoknowthefreecapacityspacesothatyoucandeterminethesizeof thelogicaldrive.
Thenumberofdiskdrives youcanincludeina arrayisconstrainedbythecapacityof eachdisk drive. thefollowingtable relatesthecapacityofindividual diskdrivestothenumberofdiskdrives thatyou canincludeinaarray.
Table12.MaximumNumberofDiskDrivesinaArrayBasedonCapacity
Controller firmware PRIOR to 7.10 (DS4000) or 6.xx (DS3000)
Controller firmware 7.10 or later (DS4000 / DS5000 only) Numberofdrivesper
array
30forallRAIDlevels v RAID3andRAID5:30drives
v RAID0andRAID1:Maximumofdrives supportedforagivenstoragesubsystem
Maximumlogical drivesize
2TB Numberofdrivesinanarraymultipliedby thesizeofthesmallestcapacitydriveinthe array
Note: Some ofthediskdrivecapacitycontains metadatainformation,sotheactualusablecapacityis somewhatless.Also,somestoragesubsystemslimitthesizeof thearrayto2 TB,andsomehost operatingsystemslimitlogicaldrivesize to2TBorless.
Youcandeterminethesizeofthearraybymultiplyingthemaximum numberofdiskdrivesin thearray bythecapacityofthesmallestdiskdriveinthearray.
Note: Some storagesubsystemspermitdifferentdrivetypesinthesameenclosure;however,youcannot haveacombinationofdifferentdiskdrivesinthesamearray.
TheRAIDlevelisthelevelof dataprotectionthatyouwanttodefineforyourstoragesubsystem.The RAIDlevelthatyouchooseaffectsstorage capacity.Whenyouconfigureyourstoragesubsystem,you mustconsider thiscompromisebetweendataprotectionand storagecapacity.Ingeneral,themore protectionthatyouneed,theless storagecapacityisavailable inyourstorage subsystem.(For a
descriptionof theRAID levelsthatyoucandefinebyusingthescriptcommands,see““RAIDLevels”on page145.)
Logical
Drives
Alogicaldriveisalogicalcomponent(object)thatisthebasicstructurethatiscreatedonthestorage subsystemtostoredata.Alogicaldriveisa contiguoussubsectionofa arraythatisconfiguredtomeet applicationneedsfordataavailabilityandI/Operformance.TheIBMStorageManagerclient software administersalogicaldriveasifthelogicaldriveisone“diskdrive”fordatastorage.Logical drivesare |
identifiedbynamesorlabelsthatuserschoose.Thelogicaldrivenamescanbeanycombinationof alphanumericcharacters,hyphens(-),and underscores(_).Themaximumlength ofalogicaldrivename is30characters.
Thescriptcommandssupportthefollowingtypesof logicaldrives:
v Standardlogicaldrive–Alogicalstructure thatistheprincipaltypeoflogicaldrivefordatastorage. Astandardlogicaldriveisthemostcommontype oflogicaldriveinastoragesubsystem.
v Accesslogicaldrive–Afactory-configuredlogicaldriveina storageareanetwork(SAN)environment thatisusedforcommunicationbetweentheIBM StorageManagerclientsoftwareandthestorage subsystemcontroller.Theaccesslogicaldriveusesalogicalunitnumber(LUN)address andconsumes 20MBofstorage space.The20MBofaccesslogicaldrivestoragespaceisnotavailablefordata storage.
Note: Youmust usetheaccesslogicaldriveonlyforin-band-managedstoragesubsystems.
v FlashCopylogicaldrive–Alogicalpoint-in-timeimageofanotherlogicaldrive.Aflashcopylogical driveisthelogicalequivalentofa completephysicalcopy;however,itisnotanactual,physical copy. Instead,thefirmwaretracksonlythedatablocksthatare overwrittenandcopiesthoseblockstoa flashcopyrepositorylogicaldrive.
v FlashCopyrepositorylogicaldrive–Aspeciallogicaldriveinthestoragesubsystemthatiscreatedas aresourcefora flashcopylogicaldrive.Aflashcopyrepositorylogicaldrivecontainsflashcopydata andcopy-on-writedatafora particularflashcopylogicaldrive.
v Baselogicaldrive–Astandardlogicaldrivefromwhichyoucreateaflashcopylogicaldrive.The term“baselogicaldrive”isusedonlytoshowtherelationship betweena standardlogicaldrivefrom whichyouare takingthepoint-in-timeimageanda flashcopylogicaldrive.
v Primarylogicaldrive–Astandardlogicaldrive inaEnhancedRemoteMirroringrelationship.The primarylogicaldriveacceptshostdatatransfersandstoresapplicationdata.Whenyoufirstcreatethe mirrorrelationship,datafromtheprimarylogicaldriveiscopied initsentirety totheassociated secondarylogicaldrive.
v Secondarylogicaldrive–Astandardlogicaldriveina EnhancedRemoteMirroringrelationship that maintainsamirror(orcopy)ofthedatafromitsassociatedprimarylogicaldrive.Thesecondary logicaldriveremainsunavailabletohostapplicationswhilemirroringisunderway.Intheeventofa disasteroracatastrophicfailureoftheprimarysite, asystem administratorcanpromotethesecondary logicaldrivetoaprimaryrole.
v Mirrorrepositorylogicaldrive–AspeciallogicaldriveinaEnhancedRemoteMirroring
configurationthatiscreatedasa resourceforeachcontrollerinboththelocalstorage subsystemand theremotestoragesubsystem.Thecontrollerstoresmirroringinformationonthislogicaldrive, includinginformationaboutremote writesthatarenotyetcomplete.Acontrollercanusethis informationtorecoverfromcontrollerresetsandaccidentalpowershutdownofthestorage subsystems.
Note: FlashCopy LogicalDriveand EnhancedRemoteMirroringarepremiumfeaturesthatyoumust activatebefore youcanusethem.Formore informationaboutFlashCopy logicaldrives,seeChapter5, “UsingtheFlashCopy PremiumFeature,”onpage163.For moreinformationaboutEnhancedRemote Mirroring,seeChapter6,“UsingtheEnhancedRemoteMirroringPremiumFeature,”onpage171.