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Removing IBMtape

In document Installation and User s Guide (Page 189-192)

Use thepkgrmcommandtoremovetheIBMtapepackagefromthesystem.

% /usr/sbin/pkgrm IBMtape

All activeprocessesusinganyIBMdevicessupportedbytheIBM SCSITapeand MediumChangerDevice DriverforSolaris mustbe stoppedinorderforthe removal proceduretocompletesuccessfully.

Note: BeforeVersion4.0.0.0oftheIBMSCSI TapeandMediumChangerDevice DriverforSolaris, thedriverconsistedoftwoseparatedevicedriver components:stddsupportedIBM SCSItapedrives,and smcddsupported IBMSCSI mediumchangers.ThesingleIBMtapepackagenow combines thesetwodriversandprovides allofthefunctionprovidedpreviouslyby thesmcddandstddpackages.Youmust removebothofthesepackagesfrom yoursystem beforeinstallingIBMtape.

Toremovethesepackages,enterthefollowingtwocommands:

% /usr/sbin/pkgrm smcdd

% /usr/sbin/pkgrm stdd

Configuration Parameters

WhenusingdevicesthatIBMtapecontrols,certain devicecharacteristics,suchas thedefaultblocksize,canbecontrolled throughthedevicedriverconfiguration file.TheIBMtapeconfigurationfileisnamedIBMtape.conf.Theworkingcopyof this fileislocatedinthe/usr/kernel/drvdirectory.

Duringinstallationof IBMtape,theworkingcopyofIBMtape.conf ispreserved,ifit exists.DuringremovalofIBMtape,theworkingcopyofIBMtape.confisnot

deleted.Theseconventionsallowconfigurationsettingstoremainacrossupdatesof IBMtape.Areference copyofIBMtape.confwithfactory defaultsettingsisalways installedinthe/opt/IBMtapedirectory.

Note: IBMrequiresthattheSolarisnativeSCSI tapedevicedriverstbeconfigured sothatit doesnotattempttosupportSCSItargetsthatIBMtapecontrols.

See“PreventingConflictswithOther DeviceDrivers”onpage161 formore informationaboutmultipledriveraccesstoadevice.

Attention: Failuretopreventmorethanonedevicedriverfromoperatingthe same SCSItapedrive maycausesystempanicsordatalossonthetapedrive.

Configurationsettingsareapplied onlyat boottimeorwhenIBMtapeisunloaded manuallyfrom,then reloadedinto,memory.Ifyouchangeconfigurationsettingsin IBMtape.conf,youcanmakethechangeseffectivebyrebootingthesystem.Asan alternativetorebooting, ensurethatnoIBMtapeowneddevicesare inuse,then issue thefollowing:

% /usr/sbin/rem_drv IBMtape

% /usr/sbin/add_drv -m ’* 0666 bin bin’ IBMtape

Default settingsinIBMtape.confcanbeoverriddenfor aparticulardevice(andonly whilethedeviceiskeptopen)usingtheioctlapplicationprogramminginterface (API)ofthedevicedriver.The parametersettingsmadethroughtheAPIrevert backtothedefaultvaluesinIBMtape.confthenexttimethatthedeviceisopened.

See theIBM UltriumDeviceDrivers: ProgrammingReference formoreinformation aboutchangingconfigurationparametersunderprogramcontrol.

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Chapter32.Installation,Removal,andConfiguration 169

IBMtape.conf containsonestanzaforeachSCSI targetaddress/LUNpairownedby IBMtape.ThereferenceIBMtape.conf filesupplied withthepackagecontains a stanza foreverypossibleSCSItarget andLUNcombinationsupportedbyIBM tape subsystems.

The followingexampleshows thestanza fortarget0,LUN0, withIBMtape’s defaultconfigurationparametervalues.Theparameterimmediateisdisabled, whichmeansthatSCSI commandsWrite FM,Locate,Load-Unload,Erase,and Rewindcompletebeforereturningstatus:

name="IBMtape" class="scsi"

The followingexampleshows thestanza fortarget0,LUN0, withIBMtape’s defaultconfigurationparametervaluesand therewindimmediatemodeset on, whichcausestheSCSIrewindcommandtoreturncontroltotheapplication programbefore thecommandactuallycompletesonthetapedrive:

name="IBMtape" class="scsi"

Ifimmediateisset to1andrew_immediateissetto0,thesettingof rew_immediateisignored.

The namevariableidentifies IBMtapeasthedevicedriver,andclassidentifies the type ofdevicesupportedasSCSI.

The targetandthelunvariablesdeterminethetarget addressandLUNofIBM devices thatarecontrolledbythatstanza.Onsystemswithmultiple SCSIadapters, a singletarget/LUNstanzacontrolstheconfigurationsettingsforalldevices addressedwiththattarget addressandLUN.Thus,twoormoresupportedIBM devices onthesystem thathavethesametarget andLUNsettingsbutare attached todifferentSCSI busesareallaffectedbytheconfigurationparametersofthe single stanzahavingthattargetaddress andLUN.

AfterinstallationoftheIBMtapepackageiscomplete,youmayeliminate

unnecessaryprobing fordevicesbycommentingoutunused targetandLUNpairs.

Inthisexample,thestanzasfortarget0,LUN 0andtarget 0,LUN1 havebeen commented out.Thoseaddressand LUNcombinationsare notprobed,which savestimeduringa rebootormanualreloadofIBMtape.However, ifanIBM deviceisaddressedattarget0, LUN0ortarget 0,LUN1,it isnotdetected.

#name="IBMtape" class="scsi"

# block_size=0

# buffering=1

# immediate=0

# trailer=0

# sili=0;

Theremainingfiveconfigurationparametersaffectthebehaviorofthedevice driverspecificallyfortheIBMdeviceordevices associatedwiththatstanza(target and LUN).Allof theseparametersare specificonlytotapedrivedeviceoperation and havenoeffectonmediumchangerdevicebehavior.Thedefaultconfiguration parametersareadequateformostpurposes.However, thevaluesinthe

configurationfilecanbemodifiedtosuitthespecific requirementsofthe application ortheuser.

Remember thatmodifyinga valueintheconfigurationfiledeterminesthevalue of theparameterat deviceopentime.Whileopen,thevalue ofaparametercanbe alteredusinganioctlfunction call,butthechangeiseffectiveonlywhilethedevice remainsopen.Workingconfigurationparametersrevertbacktothedefaultvalues (established bytheconfigurationfile)whenthedeviceisclosedandreopened.See theIBMUltriumDeviceDrivers:ProgrammingReferenceformore informationabout changing configurationparametersbywayofprogramcontrol.

Thefollowinglistdescribes theset ofconfigurationparametersrecognizedbythe IBMtapedevicedriver:

v block_size(0=variablelength)Thisoptionspecifies thedeviceblock sizethatis establishedwiththeSCSIModeSelect commandduring anopenfunctioncall.

Untilthisvalueischanged,itistheworkingblocksize.Variableblocksizeis establishedusingavalue ofzero.Anyotherpositivevaluerepresentsa fixed blocksize.Themaximum supportedblocksizevariesforeachtapedevice.See theappropriatehardwarereferencemanual.

Note: IBMtapedoesnotallowodd bytecount fixedblockreadsorwrites.For instance,a fixedblocksizeof4096or4098isallowed,but4097isnot.If youattempttoread orwriteusinganodd byte-count fixedblocksize, thereadorwritereturns-1,witherrno setto22,invalidargument.Ifyou must readorwriteoddbytecountblocks,set blocksize to0(variable blocksize),thentransfer oneblock’sworthofdataperread orwrite.

v buffering(0=Off,1=On)Whena writecommandisprocessed,thedataiseither storeddirectlyonthephysicaltapeorbufferedindevicehardware.Buffering canbe turnedOnandOff withthis option.Ifbufferingisdisabled,theeffective performanceofthedevicemaybeseriouslydegraded,because thetapedevices cannottakeadvantageoftheirbuffering optimization.Bufferflushing(or committingdatatothetape)canbe controlledbytheapplication throughthe STIOC_SYNC_BUFFERioctl function.

v immediate(0=Off,1=On)Ifimmediateissetto0, theSCSI commandsWriteFM, Locate,Load-Unload,Erase,andRewindreturnwith statuswhenthecommand actuallycompletesonthetapedrive.Ifimmediateissetto1,these commands returnwithstatusbefore thecommandactuallycompletes.

v rew_immediate(0=Off,1=On)Ifrew_immediateissetto0,theSCSIRewind commandreturnswithstatuswhenthecommandactuallycompletesonthetape drive.Ifit isset tosetto1,theRewindcommandreturnswith statusbeforethe commandactuallycompletes.Ifimmediateissetto1, thesettingof

rew_immediateisignored.

v trailer(0=Off,1=On)Ifa tapedriveencounterslogicalend-of-tape(EOT) during awriteoperation,itreturnsa checkconditionstatus.Thedriverreturns0bytes

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Chapter32.Installation,Removal,andConfiguration 171

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writtentonotifytheapplication ofthisEOTsituation.Acheck conditionis returnedbythetapedriveforeverysubsequent writeoperationwhenpastEOT.

Iftrailerisenabled,writingrecordspastEOTisallowedbythedevicedriver.

FollowingthefirsttimethewriteoperationnotifiestheapplicationofEOT,all subsequentEOTnotificationsaresuppressed bythedriver,and theactual numberofbyteswrittenisreturned. Whenthephysicalendofmediaisreached, allwriteoperations failwitha returncodeof-1,regardlessofthetrailersetting.

Whentrailerisenabled,managingthemedia pastEOTistheapplication’s responsibility.

v sili(0=Off,1=On)Normally,during areadoperation,ifa largerblockofdatais requestedthanisactuallyreadfromthetape,thetapedeviceraisesacheck condition.TheIBMtapedevicedrivermust performerrorhandlingprocedures, whichaddsoverheadtothereadoperation.TheIBMtapedriverdoesnotsurface thisasanerrorconditiontotheapplicationandultimatelyreturnstheactual numberofbytesread.However, thisdrivererrorprocessingdoesresult inless thanoptimumread performanceinsomescenarios.WhenSILImodeisenabled, thetapedeviceisforcedtoSuppress IllegalLengthIndicationduring read operations.Thiseliminatestheerrorprocessingperformedbythedriverand resultsinimproved readperformanceforsomescenarios.Theactualnumberof bytesreadisstillreturnedtotheapplication inSILImode.

In document Installation and User s Guide (Page 189-192)

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