TheFlashCopypremiumfeaturecreatesa FlashCopylogicaldrivethatyoucanuseasa backupofyour data.AFlashCopylogicaldriveisa logicalpoint-in-timeimageofastandardlogicaldrive.Becauseitis notaphysicalcopy,a FlashCopylogicaldriveiscreatedmorequicklythanaphysical copyandrequires lessstoragespaceonthedisk drive.Typically,youcreateaFlashCopylogicaldrivesothatan application, suchasa backupapplication, canaccesstheFlashCopylogicaldriveandread thedatawhilethebase logicaldrivestays onlineand useraccessible.YoucanalsocreateseveralFlashCopylogicaldrivesof a baselogicaldriveandwritedatatotheflashcopylogicaldrives toperformtestingandanalysis. FlashCopylogicaldrivesprovidethesecapabilities:
v Createacompleteimageof thedataona baselogicaldriveataparticularpoint intime v Useonlyasmallamountofstorage space
v Provideforquick,frequent,non-disruptivebackups,ortestingnewversionsof adatabasesystem withoutaffecting realdata
v ProvideforFlashCopylogicaldrivestobe read,written,andcopied
v Usethesameavailabilitycharacteristicsofthebaselogicaldrive(suchasRAID protectionand redundantpathfailover)
v MappingtheFlashCopylogicaldriveandmakingit accessibletoanyhostonastorage areanetwork (SAN).YoucanmakeFlashCopydataavailable tosecondaryhostsforread accessand writeaccessby mappingtheFlashCopytothehosts
v CreatinguptofourFlashCopiesperlogicaldrive(themaximumnumberofFlashCopylogicaldrives is one-halfofthetotalnumberof logicaldrives thataresupportedbythecontroller)
v Increasingthecapacityofa FlashCopylogicaldrive
How
FlashCopy
Works
Threecomponentscomprisea FlashCopylogicaldrive:thebase logicaldrive,theFlashCopylogicaldrive, andtheFlashCopyrepositorylogicaldrive.The followingtable liststhecomponentsandbrieflydescribes whattheydo.
Table18.ComponentsofaFlashCopyLogicalDrive
Component Description
Baselogicaldrive AstandardlogicaldrivefromwhichtheFlashCopyis created
FlashCopylogicaldrive Alogicalpoint-in-timeimageofastandardlogicaldrive FlashCopyrepositorylogical
drive
AlogicaldrivethatcontainsFlashCopymetadataand copy-on-writedataforaparticularFlashCopylogical drive
Basedoninformationthatyouprovidethrough thescriptcommands,thestoragemanagementsoftware createsanemptyFlashCopyrepositorylogicaldriveanddefinesthemappingfromabaselogicaldriveto theFlashCopyrepositorylogicaldrive.TheFlashCopy repositorylogicaldriveholdschangeddatathata hostwritestothebaselogicaldrive.WhentheFlashCopyrepositorylogicaldriveisfirst created,itholds onlythemetadataabouttheFlashCopy logicaldrivewith whichitisassociated.
Note: Whenyoufirst createaFlashCopyrepositorylogicaldrive,brieflystop allofthewriteoperations tothebaselogicaldrivesothatastableimageof thebase logicaldriveisavailable.
Whenthehostwritestothebaselogicaldrive,thenew dataisalsocopiedtotheFlashCopyrepository logicaldrive.Thisactioniscalledcopy-on-write.AFlashCopyisconstructedbycombiningtheupdated dataintheFlashCopyrepositorylogicaldrivewith datainthebaselogicaldrivethathasnotbeen altered.Thisactioncreatesa completecopyofthebaselogicaldriveat aspecific pointintime.The FlashCopyappearsasa logicaldrivethatcontains theoriginaldataatthetimeofcreation,butthe FlashCopyisactuallyanimagethatisthecombinationoftheFlashCopy repositorylogicaldriveandthe originalbase logicaldrive.TheFlashCopyrepositorylogicaldrive,whichhousesoriginaldatathathas beenchanged,istheonlyadditionaldiskdrivespacethatisneededfortheFlashCopylogicaldrive.The additionaldiskdrivespaceistypically10percentto20percentofthediskdrivespaceofthebaselogical driveandvariesdependingontheamount ofchangestothedata.Thelongera FlashCopylogicaldrive isactive,thelargertheFlashCopyrepositorylogicaldrivemust be.Thedefaultsizeof theFlashCopy repositorylogicaldriveis20percentofthebaselogicaldrive;however,youcansetthesizeofthe FlashCopyrepositorylogicaldrivetoothervalues.
Youcanread, write,andcopy aFlashCopylogicaldrive.Datawritten bya hosttotheFlashCopy logical driveishandledintheFlashCopyrepositorylogicaldrive.Whena writeoccurstothebaselogicaldrive ofaFlashCopy logicaldrive,thenewdataalso overwritestheappropriateFlashCopyrepositorylogical drivedata.Thefollowingtable liststheFlashCopylogicaldrivecommands.
Table19.FlashCopyLogicalDriveCommands
Command Description
createflashcopyLogicalDrive ThiscommandcreatesaFlashCopylogicaldrive. recreateflashcopy Thiscommandstartsafreshcopy-on-writeoperation
byusinganexistingFlashCopylogicaldrive. recreateflashcopycollection ThiscommandrestartsmultipleFlashCopylogical
drivesasonebatchoperationusingoneormany existingFlashCopylogicaldrives.
set(flashcopyLogicalDrive) Thiscommanddefinesthepropertiesfora FlashCopylogicaldriveandletsyourenamea FlashCopylogicaldrive.
stopflashcopy Thiscommandstopsacopy-on-writeoperation.
Creating
a
FlashCopy
Logical
Drive
ThecreateFlashCopyLogicalDrivecommandprovidesthreemethodsfordefiningthediskdrivesforyour FlashCopyrepositorylogicaldrive:
v DefiningthediskdrivesfortheFlashCopy repositorylogicaldrivebytheirenclosureIDsandtheirslot IDs
v Defininga arrayinwhichtheFlashCopy repositorylogicaldriveresides.Inaddition,youcandefine thecapacityoftheFlashCopy repositorylogicaldrive.
v Definingthenumberofdiskdrives, butnotspecific diskdrives,fortheFlashCopyrepositorylogical drive.
WhenyouusethecreateFlashCopyLogicalDrivecommandtocreateaFlashCopy logicaldrive,the minimuminformationthatyouneedtoprovideisthestandardlogicaldrivethatyouwanttouseforthe baselogicaldrive.Whenyoucreatea FlashCopylogicaldrivebyusingminimuminformation,the storagemanagementsoftware providesdefaultvaluesfortheotherpropertyparametersthatarerequired foracompletely definedFlashCopy logicaldrive.
Creating
a
FlashCopy
Logical
Drive
with
User-Assigned
Disk
Drives
CreatingaFlashCopy logicaldrivebyassigningthediskdrivesprovidesflexibility indefiningyour configurationbylettingyouchoosefromtheavailable diskdrivesinyour storagesubsystem.Whenyou
choosethediskdrivesforyour FlashCopylogicaldrive,youautomaticallycreateanewarray.Youcan specifywhichdisk drivestouseandtheRAIDlevelforthenewarray. Thecommandtakesthis form:
create flashcopyLogicalDrive baseLogicalDrive=”baseLogicalDriveName” [repositoryRAIDLevel=(1 | 3 | 5 | 6)
(repositoryDrives=(enclosureID1,slotID1 ... enclosureIDn,slotIDn) userLabel=”flashcopyLogicalDriveName” warningThresholdPercent=percentValue repositoryPercentOfBase=percentValue repositoryUserLabel=”repositoryName” repositoryFullPolicy=(failBaseWrites | failFlashCopy)] [enclosureLossProtect=(TRUE | FALSE)]
Thisexampleshowsa commandin whichusersassignthedisk drives:
c:\...\...\client>smcli 123.45.67.89 -c “create flashcopyLogicalDrive
baseLogicalDrive=\”Mars_Spirit_4\” repositoryRAIDLevel=5 repositoryDrives=(1,1 1,2 1,3 1,4 1,5);”
Thecommandinthis examplecreatesa newFlashCopyofthebaselogicaldriveMars_Spirit_4.The FlashCopyrepositorylogicaldriveconsistsof fivediskdrivesthatforma newarray.Thenew arrayhasa RAIDlevelof5.Thiscommandalsotakes aFlashCopyofthebaselogicaldrive,whichstartsthe
copy-on-writeoperation.
Thisexampleshowshow tousethecommandinascriptfile:
create flashcopyLogicalDrive baseLogicalDrive=”Mars_Spirit_4” repositoryRAIDLevel=5 repositoryDrives=(1,1 1,2 1,3 1,4 1,5);
Thisexampleshowsa minimalversionofthecommand:
c:\...\...\client>smcli 123.45.67.89 -c “create flashcopyLogicalDrive baseLogicalDrive=\”Mars_Spirit_4\”;”
Thecommandinthis examplecreatesa newFlashCopyforthebaselogicaldriveMars_Spirit_4.The FlashCopyrepositorylogicaldriveiscreatedin thesamearray asthebaselogicaldrive,whichmeans thattheFlashCopy repositorylogicaldrivehasthesameRAIDlevelasthebaselogicaldrive.This commandstartsthecopy-on-writeoperation.
Thisexampleshowshow tousethecommandinascriptfile:
create flashcopyLogicalDrive baseLogicalDrive=“Mars_Spirit_4”;
Creating
a
FlashCopy
Logical
Drive
with
Software-Assigned
Disk
Drives
WiththisversionofthecreateFlashCopyLogicalDrivecommand, youchooseanexistingarrayinwhich toplacetheFlashCopyrepositorylogicaldrive.Thestoragemanagementsoftware determineswhichdisk drivestouse.YoucanalsodefinehowmuchspacetoassigntotheFlashCopyrepositorylogicaldrive. Becauseyouare usinganexistingarray,theRAIDlevelfortheFlashCopylogicaldrivedefaultstothe RAIDlevelofthearrayin whichyouplaceit.YoucannotdefinetheRAIDlevelfortheFlashCopy logical drive.Thecommandtakesthis form:
create FlashCopyLogicalDrive baseLogicalDrive=”baseLogicalDriveName” [repositoryArray=ArrayNumber freeCapacityArea=freeCapacityIndexNumber userLabel=”FlashCopyLogicalDriveName” warningThresholdPercent=percentValue repositoryPercentOfBase=percentValue repositoryUserLabel=repositoryName repositoryFullPolicy=(failBaseWrites | failFlashCopy)] [enclosureLossProtect=(TRUE | FALSE)]
c:\...\...\client>smcli 123.45.67.89 -c “create
FlashCopyLogicalDrive baseLogicalDrive=\”Mars_Spirit_4\” repositoryArray=2 freeCapacityArea=2;”
Thecommandinthis examplecreatesa newFlashCopyrepositorylogicaldriveinarray2.Thebase logicaldriveisMars_Spirit_4. ThesizeoftheFlashCopyrepositorylogicaldriveis4 GB.Thiscommand alsotakesa FlashCopyofthebaselogicaldrive,startingthecopy-on-writeoperation.
WhenyoudefinethecapacityofaFlashCopy repositorylogicaldrive,specifyasize thatis20percent of thesizeofthebaselogicaldrive.Inthepreviousexample,thesizeoftheFlashCopyrepositorylogical driveissetto4GB. Theunderlyingassumptionisthatthebaselogicaldrivesizeis20GB(0.2x20GB= 4GB).
Thisexampleshowshow tousethecommandinascriptfile:
create FlashCopyLogicalDrive baseLogicalDrive=”Mars_Spirit_4” repositoryArray=2 freeCapacityArea=2;
Creating
a
FlashCopy
Logical
Drive
by
Specifying
a
Number
of
Disk
Drives
WiththisversionofthecreateflashcopyLogicalDrivecommand,youmustspecifythenumberofdisk drivesandtheRAIDlevelthatyouwantfortheFlashCopyrepositorylogicaldrive.Thisversionofthe createflashcopyLogicalDrivecommandcreates anewarray.Youmust havedisk drivesinthestorage subsystemthatarenotassignedtoaarrayforthiscommandtowork.
create flashcopyLogicalDrive baseLogicaldrive=”baseLogicalDriveName” [repositoryRAIDLevel=(1 | 3 | 5 | 6)
repositoryDriveCount=numberOfDrives
driveType=(fibre | SATA | SAS) userLabel=”flashcopyLogicalDriveName” warningThresholdPercent=percentValue repositoryPercentOfBase=percentValue repositoryUserLabel=”repositoryName” repositoryFullPolicy=(failBaseWrites | failFlashCopy)] [enclosureLossProtect=(TRUE | FALSE)]
Thisexampleshowshow tousea commandinwhichusersspecifythenumberofdiskdrives:
c:\...\...\client>smcli 123.45.67.89 -c “create flashcopyLogicalDrive
baseLogicalDrive=\”Mars_Spirit_4\” repositoryRAIDLevel=5 repositoryDriveCount=3;”
Thecommandinthis examplecreatesa newFlashCopyrepositorylogicaldrivethatconsistsofthreedisk drives.Threediskdrivescomprisea newarraythathasa RAIDlevelof5.Thiscommandalsotakes a FlashCopyofthebaselogicaldrive,whichstartsthecopy-on-writeoperation.
Thisexampleshowshow tousethecommandinascriptfile:
create flashcopyLogicalDrive baseLogicalDrive= “Mars_Spirit_4” repositoryRAIDLevel=5 repositoryDriveCount=3;
User-Defined
Parameters
UsetheparametersinthecreateflashcopyLogicalDrivecommandtodefinetheFlashCopylogicaldriveto suittherequirementsofyourstorage subsystem.Thefollowingtablelists theparametersandbriefly describeswhattheparametersdo.
Table20.FlashCopyLogicalDriveParameters
Parameter Description
driveType Thetypeofdiskdrivethatyouwanttouseforthe
FlashCopyrepositorylogicaldrive.Validdiskdrivetypesare fibre,SATA,orSAS.Thisparameterworksonlywiththe count-basedrepositorymethodofdefiningaFlashCopy logicaldrive.
repositoryArray ThearrayinwhichyouwanttobuildtheFlashCopy repositorylogicaldrive.Thedefaultvalueistobuildthe FlashCopyrepositorylogicaldriveinthesamearrayasthe baselogicaldrive.
freeCapacityArea Theamountofstoragespacethatyouwanttouseforthe FlashCopyrepositorylogicaldrive.Freestoragespaceis definedinunitsofbytes,KB,MB,GB,orTB.
userLabel ThenamethatyouwanttogivetotheFlashCopylogical drive.IfyoudonotchooseanamefortheFlashCopylogical drive,thesoftwarecreatesadefaultnamebyusingthebase logicaldrivename.Forexample,withabaselogicaldrive nameofMars_Spirit_4:
v
WhenthebaselogicaldrivedoesnothaveaFlashCopy logicaldrive,thedefaultFlashCopylogicaldrivenameis Mars_Spirit_4-1.
v
Whenthebaselogicaldrivealreadyhasn-1numberof FlashCopylogicaldrives,thedefaultnameis
Mars_Spirit_4-n.
repositoryUserLabel
ThenamethatyouwanttogivetotheFlashCopyrepository logicaldrive.IfyoudonotchooseanamefortheFlashCopy repositorylogicaldrive,thesoftwarecreatesadefaultname byusingthebaselogicaldrivename.Forexample,ifthebase logicaldrivenameisMars_Spirit_4anddoesnothavean associatedFlashCopyrepositorylogicaldrive,thedefault FlashCopyrepositorylogicaldrivenameisMars_Spirit_4-R1. Ifthebaselogicaldrivealreadyhasn-1numberofflashcopy repositorylogicaldrives,thedefaultnameis
Mars_Spirit_4-Rn.
warningThresholdPercent Thepercentageofthecapacitythatyouwillpermitthe FlashCopyrepositorylogicaldrivetogetbeforeyoureceivea warningthattheFlashCopyrepositorylogicaldriveis nearingfull.Thewarningvalueisapercentageofthetotal capacityoftheFlashCopyrepositorylogicaldrive.The defaultvalueis50,whichrepresents50percentofthetotal capacity.(Youcanchangethisvaluelaterbyusingtheset flashcopyLogicalDrivecommand.)
repositoryPercentOfBase ThesizeoftheFlashCopyrepositorylogicaldriveasa percentageofthebaselogicaldrivesize.Thedefaultvalueis 20,whichrepresents20percentofthebaselogicaldrivesize.
repositoryFullPolicy ThetypeofFlashCopyprocessingthatyouwanttocontinue iftheFlashCopyrepositorylogicaldriveisfull.Youcan choosetofailwritestothebaselogicaldrive(failBaseWrites) orfailwritestotheFlashCopylogicaldrive(failFlashCopy). ThedefaultvalueisfailFlashCopy.
c:\...\...\client>smcli 123.45.67.89 -c “create flashcopyLogicalDrive baseLogicalDrive=\”Mars_Spirit_4\” repositoryRAIDLevel=5 repositoryDriveCount=5 driveType=fibre userLabel=\”Mars_Spirit_4_snap1\” repositoryUserLabel=\”Mars_Spirit_4rep1\” warningThresholdPercent=75 repositoryPercentOfBase=40 repositoryFullPolicy=failSnapShot;”
Thisexampleshowshow tousethecommandinascriptfile:
create flashcopyLogicalDrive baseLogicalDrive=”Mars_Spirit_4” repositoryRAIDLevel=5 repositoryDriveCount=5 driveType=fibre userLabel=”Mars_Spirit_4_snap1”
repositoryUserLabel=”Mars_Spirit_4_rep1”
warningThresholdPercent=75 repositoryPercentOfBase=40 repositoryFullPolicy=failSnapShot;
FlashCopy
Logical
Drive
Names
and
FlashCopy
Repository
Logical
Drive
Names
TheFlashCopylogicaldrivenamesandtheFlashCopyrepositorylogicaldrivenamescanbe any combinationofalphanumericcharacters,hyphens,andunderscores.Themaximumlengthofthelogical drivenamesis30characters.Youmustenclosethelogicaldrivenameindoublequotationmarks.The characterstringcannotcontainanewline. Makesurethatyouuseuniquenames;if youdonotuse uniquenames,thecontrollerfirmwarereturnsanerror.
Onetechniquefor namingtheFlashCopylogicaldriveandtheFlashCopyrepositorylogicaldriveisto addahyphenatedsuffixtotheoriginalbaselogicaldrivename.Thesuffixdistinguishesbetweenthe FlashCopylogicaldriveandtheFlashCopyrepositorylogicaldrive.Forexample,ifyouhavea base logicaldrivewith anameofEngineeringData,theFlashCopylogicaldrivecanhavea nameof EngineeringData-S1,andtheFlashCopyrepositorylogicaldrivecanhaveanameofEngineering Data-R1.
Ifyoudo notchoose auniquenameforeithertheFlashCopylogicaldriveortheFlashCopyrepository logicaldrive,thecontrollerscreatea defaultnamebyusingthebase logicaldrivename. Theseexamples areFlashCopylogicaldrivenamesthatthecontrollersmightcreate:
v Ifthebaselogicaldrivenameisaaaand doesnothavea FlashCopylogicaldrive,thedefault FlashCopylogicaldrivenameisaaa1.
v Ifthebaselogicaldrivealreadyhasn-1 numberofFlashCopylogicaldrives,thedefaultnameisaaa-n. v Ifthebaselogicaldrivenameisaaaand doesnothavea FlashCopyrepositorylogicaldrive,the
defaultFlashCopyrepositorylogicaldrivenameisaaa-R1
v Ifthebaselogicaldrivealreadyhasn-1 numberofFlashCopyrepositorylogicaldrives,thedefault nameisaaa-Rn.
Intheexamples fromtheprevious section,theuser-definedFlashCopylogicaldrivenamewas Mars_Spirit_4_snap1,andtheuser-definedFlashCopyrepositorylogicaldrivenamewas
Mars_Spirit_4_rep1.ThedefaultnamethatwasprovidedbythecontrollerfortheFlashCopylogicaldrive wasMars_Spirit_4-1.ThedefaultnamethatwasprovidedbythecontrollerfortheFlashCopyrepository logicaldrivewas Mars_Spirit_4-R1.
Changing
FlashCopy
Logical
Drive
Settings
Usetheset(FlashCopy)logicalDrivecommandtochangethesepropertysettingsfora FlashCopylogical drive:
v TheFlashCopylogicaldrivename v Thewarningthresholdpercent v TheFlashCopyrepositoryfullpolicy
Thisexampleshowshow tochangeaFlashCopy logicaldrivename.
c:\...\...\client>smcli 123.45.67.89 -c “set logicalDrive [\”Mars_Spirit_4-1\”] userLabel=\”Mars_Odyssey_3-2\”;”
Thisexampleshowshow tousethecommandinascriptfile:
set logicalDrive [“Mars_Spirit_4-1”] userLabel=”Mars_Odyssey_3-2”;
WhenyouchangethewarningthresholdpercentandtheFlashCopyrepositoryfullpolicy,youcanapply thechangestooneorseveralFlashCopylogicaldriveswith thiscommand.Thisexampleshowshowto usetheset(FlashCopy) logicalDrivecommandtochangethese propertiesonmorethanoneFlashCopy logicaldrive:
c:\...\...\client>smcli 123.45.67.89 -c “set logicalDrive [\”Mars_Spirit_4-1\” \”Mars_Spirit_4-2\” \”Mars_Spirit_4-3\” warningThresholdPercent=50
repositoryFullPolicy=failBaseWrites;”
Thisexampleshowshow tousethecommandinascriptfile:
set logicalDrive [“Mars_Spirit_4-1” “Mars_Spirit_4-2” “Mars_Spirit_4-3”] warningThresholdPercent=50
repositoryFullPolicy=failBaseWrites;
Stopping,
Restarting,
and
Deleting
a
FlashCopy
Logical
Drive
WhenyoucreateaFlashCopy logicaldrive,copy-on-writestartsrunningimmediately.Aslongasa FlashCopylogicaldriveisenabled,storage subsystemperformanceisimpactedbythecopy-on-write operationstotheassociatedFlashCopyrepositorylogicaldrive.
Ifyounolongerwantcopy-on-writeoperationstorun, youcanusethestopflashcopylogicalDrive commandtostop thecopy-on-writeoperations.Whenyoustop aFlashCopylogicaldrive,theFlashCopy logicalDriveandtheFlashCopyrepositorylogicaldrivearestilldefinedforthebaselogicaldrive.Only copy-on-writehasstopped.Thisexampleshowshow tostopaFlashCopy logicaldrive:
c:\...\...\client>smcli 123.45.67.89 -c “stop flashcopy logicalDrives [\”Mars_Spirit_4-2\” \”Mars_Spirit_4-3\”];”
Thisexampleshowshow tousethecommandinascriptfile:
stop flashcopy logicalDrives [“Mars_Spirit_4-2” “Mars_Spirit_4-3”];
Whenyoustopthecopy-on-writeoperationsforaspecific FlashCopylogicaldrive,onlythatFlashCopy logicaldriveisdisabled.AlloftheotherFlashCopylogicaldrivesstayinoperation.
Whenyouwanttorestart acopy-on-writeoperation,usetherecreateflashcopylogicalDrivecommandor