ConversationalAvailabilityfortheAlways-On

Enterprise

ByNickCavalancia

Copyright©2015

ConversationalAvailabilityfortheAlways-OnEnterprisePublishedbyConversationalGeekInc.

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PublisherAcknowledgments

Allofthefolksresponsibleforthecreationofthisguide:

Author: NickCavalancia

ProjectEditor: J.PeterBruzzese

CopyEditor: JohnRugh

ContentReviewers: ShannaG.Giarrano

NotefromtheAuthor

Weallknowthesimpletruthofupisgood,downisbad.But,applicationscrash,hardwarefails,anddatabecomescorrupt–it’soneofthereasonswehaveajobinthefirstplace!

So,isitevenpossibletogetoperationstoanalways-onstatewhereavailabilityisthenorm?

I’lltrytoprovidethebestanswerpossible,butasyoucanseefromthelackofthicknessofthisbook,it’snotmeanttobeanexhaustivereferenceonestablishingavailabilityintheenterprise.Itwaswrittenwiththeintentofwalkingthroughtheneedforavailabilityandofreviewingtheimprovementsintechnologyandstrategythatassistingettingtoavailability.Itthenaimstoshowyouthatit’sreally,reallypossibletodaytoactuallyachievebothavailabilityofmission-criticalapplications,andtobecomeanalways-onenterprise.

So,grabacomfortablechair,andlet’sdiveintowhatit’sgoingtotaketogettothealways-onenterprise.

-NickCavalancia

The“Conversational”Method

Wehavetwoobjectiveswhenwecreatea“Conversational”book:First,tomakesureit’swritteninaconversationaltonesoit’sfunandeasytoread.Second,tomakesureyou,thereader,canimmediatelytakewhatyoureadandincludeitinyourownconversations(personalorbusiness-focused)withconfidence.

Thesebooksaremeanttoincreaseyourunderstandingofthesubject.Terminology,conceptualideas,trendsinthemarket,andevenfringesubjectmatterarebroughttogethertoensureyoucanengageyourcustomer,team,co-worker,friendandeventheknow-it-allBestBuygeekonalevelplayingfield.

“GeekintheMirror”Boxes

Weinfusehumorintoourbooksthroughbothcartoonsandlightbanterfromtheauthor.Whenyouseeoneoftheseboxes,it’stheauthorsteppingoutsidethedialogtospeakdirectlytoyou.Itmightbeananecdote,itmightbeapersonalexperienceorgutreactionandanalysis,itmightjustbeasarcasticquip,butpleasedon’tskipthese“geekinthemirror”boxes.

Greetings.I’mtheauthor’sinnergeek.WithintheseboxesIcansharejustaboutanythingonthesubjectathand.Read’em!

Demandforthe“Always-On”Enterprise

Howmuchdowntimecanyourbusinessreallyhandle?Ofcourse,youhaveanimmediateanswer.ButgoaskyourCEO–dotheyhaveadifferentanswer?Perhapsevenonethat’sabitunreasonable?I’massumingyou’dcomeupwithawell-thought-outnumberofminutesorhours,basedonyourabilitytorecover,Whereas,yourCEOwilllikelyjusttellyou“none.”

Soundaboutright?

There’sareasonwhyyourCEOisthinkingthatway(andit’snotlikethey’recrazy,orhaveunrealisticdemands,right?Thatneverhappens…).Thereasonthey’rethinkingaboutzerodowntimeisbecausetheexpectationofcustomers,partners,andevenemployeesisthatservicesyouprovidearealwaysavailable.

Whileitusedtobeacceptableforevenenterprisecompaniestobe“openforbusiness”from9to5,today’scustomerdemandstheabilitytoaccessandinteractwithacompany24/7viatheirwebsite,telephone,email,andevenchat.Purchases,accountupdates,accesstodata,support,andmoreanytimeyouwantisnowthenorm.

Now,youmightthinkit’sjustlargecompanieslikeTarget,BankofAmerica,orIKEAthathavetobealwayson–butyou’dbewrong.Thinkaboutit–thesamepersonwhoisexperiencingthisgreatanytime,anywhereaccesstoinformationandservicesfromthelargercompaniesisn’tgoingtoexcuseyoujustbecauseyou’renotaslarge.They’djustwonderwhyyoucan’tprovidethesamelevelofserviceinthisdayandage…and,perhaps,moveonifyoudon’t.

So,everyorganizationneedstobeupandrunningconsistently–andthat’snoeasytask!

An“always-on”enterprise,regardlessofsize,hasinvestedinamodernizeddatacenter,wherehardwareandoperatingsystemhavebeenkeptuptodate(sonoWindowsServer2003foryou!),andnewtechnologieshavebeenembraced.

Veeamrecentlypublishedtheresultsoftheir2014DataCenterAvailabilityReport,whichrevealsonly25%oforganizationsalreadyconsidertheirdatacentertobe“modern”.Lookformorestatsfromthisreportthroughout!

What’sinaModernDataCenter?Giventhestatabove,it’slikelyyoueitherdon’thaveamoderndatacenter,areworkingtowardsone,oraren’tsureifyoudo.Thelistbelowgivesyouanideaofthemorecommoninitiativesinvolvedinmodernizingthedatacenter.

• Servervirtualization• Upgradestostorageandoperatingsystems• Dataprotectionanddisasterrecovery• Networkvirtualization• VirtualdesktopInfrastructure(VDI)• Privatecloud• InfrastructureasaService(IaaS)• SoftwareasaService(SaaS)• DisasterRecoveryasaService(DRaaS)

It’saprettytalllist,sodon’tthinkyouneedtoimplementeveryinitiativeshown.Thisismoreaguidelinetoletyouknowifyou’reorganizationismovinginthedirectionof“modern.”

Doesamoderndatacenterequatetobeingalwayson?Notnecessarily.InVeeam’sAvailabilityreport,aboutathirdoforganizationsdidnotseebeingalwaysonasakeybusinessdriverformodernizingtheirdatacenter.

Ifyourorganizationisoneofthosethatareeithernotquitethere,orhaven’tstarted,giventhesomewhatdauntinglistabove,thequestiondoesneedtoberaised“Doyouevenneedamoderndatacenter?”

Therearemorereasonsthanjustavailabilitythataredrivingthemovetoamoderndatacenter.Organizationsthathavemodernizedtheirdatacenterarefocusingeffortsonthese

newertechnologiestoloweroperationalcosts,improvesecurity,andprovidemoreefficientservices.But,intheend,itallgoesbacktocustomerandemployeeexpectationsaroundaccessingapplicationsanddatanecessaryforthemboth,andthereforetheorganization,tobeproductiveandsuccessful.

End-userdemandisapowerfulmotivatorformovingtoalwayson.InVeeam’sAvailabilityreport,63%oforganizationscited“morefrequent,real-timeinteractionsbetweencustomers,partners,suppliersandemployees”asakeydriverforminimizingdowntime.

Thatbeingsaid,ifyoustrivetoprovideanalways-oninfrastructure,themoderndatacenterissomewhatarequirement.Asyou’llseeinthisnextsection,theevolutionfromjustbackupandrestoretotrueavailabilityreliesheavilyontheexistence(andimplementation)ofnewtechnologies.

TheEvolutiontoAvailability

Availabilitytodaymeansorganizationscanrecoverfromthelossofdata,applications,systems,orlocationswithminimalorzerodowntime.Thisisarealitythatissomewhatnew.Whileit’spossibletodaytocomereallyclosetothisdefinition(thezerodowntimeisthestickingpoint),toachieveavailabilitywe’vehadtoevolveabitfrombackuptechnologiesandmethodsofyesteryeartothemoderncapabilitiesweenjoytoday.

IfyougofarenoughbackinITlikeIdo,youcanrememberatimewhensimplyhavingdaily,weekly,andmonthlybackupswereconsideredenoughtoprotectthebusiness.Backupsranatnightafterbusinesshours,andyouusedasimplegrandfather-father-sontaperotationmethodtoestablishalong-termabilitytorecover.

IfyougobackasfarinITasIdo,youcananswerthefollowingquestion:

Q:WhatwasthemaindifferencebetweenDOSv3.2andv3.3?

Whenyoustopandthinkaboutwhatkindofprotectionanightly,weekly,ormonthlybackupreallyaffordedyourorganization,yourealize,atbest,itinvolvedthelossofatleast

A:v3.3brokethe33MBpartitionbarrier!

aday’sworthofwork.Fast-forwardtotodayandthis,obviously,wouldn’tcutitforanAlways-onEnterprise.

Recoveringbacktoyesterday?Seriously?

So,what’skeptyoufromgettingto“always-on”?

Therehavebeentwosetsofconstraintsovertheyearsstoppingorganizationsfromachievingtrueavailability(that,thankfully,havebeenslowlyerodingaway):

Thefirstistheavailabletechnology.Travelinthe‘WaybackMachine’afewyearsandtheonlywaytogethighavailabilitywasusingaclusteredserver.Today,wehavesomanymoreoptionstogetdata,services,andapplicationsmovedto,andrunningon,othersystemsinalternatelocations.

Thesecondisthecostofimplementingtheavailabilitystrategy.Thestrategyyouusedependsheavilyonthetechavailabletoyou.And,asyou’llsee,ourthinkingaroundwhat’spossiblewithregardtoavailabilityhaschangedthroughtheyears.

Let’slookateachoftheseandseehowtheybenefittedtheevolutionfrombackuptoavailability.

TheevolutionofbackuptechnologyBackuptechnologyusedtolimitustoasimpleonceadaybackupbecauseoftheconstraintsinthephysicalworld.Tapesystemsonlygosofast,harddrivescanonlypulldatasoquickly,backupprocessesimpactapplicationperformanceanduserproductivity,andschedulingdowntimeduringproductionusuallywasn’tanoption.

Enterdirect-to-diskbackups,thecloudasabackuptarget,andevenhybrid-cloudbackup,alongwithmoreadvancedmethodsofdetectingchanges,deduplication,andcompression–andthetechnologybegantoempowerthebackingupoffarmoredatamuchmorequicklywhile,somehow,stillmaintainingthe

abilitytorecoverthesameamountthatusedtotakeanentirenighttobackup.Youbegintoseehowimprovementsintechnologystarttoovercomethelimitationofthephysicalworldofservers,data,andbackup.

Abackuptapedriveinthe90’shada2:1compressionratioandoftenutilizedfurthersoftware-basedcompressiontoshrinkthebackupsize.Today’schangeidentification,compressionanddeduplicationmethodscanresultinaslittleas.1%ofthetotaldatasizebeingusedtocompleteanincrementalbackup.

Thenaddinvirtualization–acompletegamechangerforavailability,andyoucouldnowbackupchangesmadetoanentiresystem,ratherthanafile,application,ordatabase.Snapshottechnology,alongwithreplicationcapabilitiestooktheconceptofneedingtobackupasubsetofdataataparticulartimeandgaveITtheabilitytohaveaccesstoabackupthatprotectedtheentiremachine,suppliedmorebackupsatfasterintervals,andfacilitatedthecopyingofthosebackupstoanotherserver.Thishadareal“WOW”factortoit!

Andastechnologyevolved,gettingusclosertoavailabilityateachturn,sodidbackupstrategies.

TheevolutionofthecostofaprotectionstrategyIpreviouslymentionedtheGrandfather-Father-Sontaperotation–thatwasabackupandrecoverystrategythat,atthetime,wascuttingedgeandhadwithstoodthetestoftime.Itscostwaspredictable(asyouonlyneededafixednumberoftapes).But,liketechnology,recoverystrategieshaveevolved,eachonesuccessivelytakingadvantageofthelatesttechnologyandfindingaloweravailabilityprice-point.

Thefollowinglist,inmore-or-lesschronologicalorder,demonstratesthechangesinthinkingfrombackuptoavailability,astechnologyhasimprovedandcosthasreduced.

• BackupandRestore–thiswasatrulyviablemethodwhenfile-levelbackupsactuallyrepresentedtheentiretyofanoperatingsystem.Thefocushereissimplyfilelevel.Eventodaywhenbackingupvirtualmachineimages,thefocusofbackupandrestoreistosimplyrestorethatimagefile.

• BackupandRecovery–thisisashiftinthegoalwhileutilizinglargelythesametechnologyasbackup&restore.It’snolongeraboutjustrestoringthedatainthebackup,butreallyconcerningitselfwithwhetheryoucangettheintendedapplicationorsystembackintooperation.

• BusinessContinuity/DisasterRecovery(BCDR)–whenthisconceptwasintroduced,wecameclosetoavailability’sintentwiththislineofthinking.Therewasashiftfromjustrecoveringasystemorapplicationtotruly“howdowegeteverythingoperationalagain.”Theproblem?Itwasseenascostly,requiringexpensiveredundanthardware,useofcoldorhotsiteslyinginwait,comparativelyslowdeliverymechanisms,suchasUPSandFedEx,gettingonaplaneyourselftoworkontheremotesysteminperson,oraccessingaremotesystemviaslowWANlinkstogetcopiesofdatatooff-sitelocations.

• UseofVirtualization–byabstractingtheneedforactualhardware,virtualizationcreatedtheabilitytoinstantlyallowredundancythroughimageandsnapshotbackupsandreplicationtooffsitelocations.

Virtualizationalsomeantfarfewerphysicalservers,therebyreducingthecostofmaintainingasecondarysite.ThisadvancedtheBCDRmovement,givingitanewmeanstoreplicateentireenvironmentsfarmorequicklyandcheaply.

• UseoftheCloud–thecloudasastoragemediumhasbroughtsimple,inexpensive,andyetsecureoffsitebackupstothemasses.However,usingitforspinningupcomputeisstillrelativelynew,anditbringsnewpossibilitiesforhavingon-demandcomputeasaresource,leveragingtheuseofvirtualizationandreplication.

• DisasterRecoveryasaService(DRaaS)–Combiningtheuseofvirtualizationandthetrustinthecloud,buildingonthesimpleconceptofahotsite,DRaaSprovides(usually)manualfailoverservicestoareplicated,hostedcopyofanythingfromasingleservertoanentirenetwork.Fortier1applications,eventhislevelofservicecanbejustified,despitethehighcost.

• RecoveryasaService(RaaS)–whileDRaaStendstofocusonthereplicationandthenfailoverofservicesintheeventofadisaster,youcanthinkofRaaSasManagedDRaaS.Thatis,insteadofsimplyprovidingafailoverenvironment,RaaSinvolvestestingofreplicatedbackupstoensureviability,continuousrecoveryofdataatverysmalltimewindows,andautomatedfailover,allowingyoutomakeverycomplexenvironmentsliveinaveryfasttimeframe.

Bylookingthroughthisevolution,youcanseesomecommonthemes:

1) It’slessaboutdata&moreaboutcontinuity–Bytheendoftheevolutiontoavailability,nooneisreallyconcernedaboutwhichfilesarebeingrecovered;onlythatthecriticalsystemsandapplicationsareavailable.

2) Ashifttowardprotectinglargerdatasets–Thiscreatestheneedforidentifyingsmallerincrementalchangestobeprotected,ratherthantheentiredatasetasawhole.

3) Smallerbackupandrecoverywindows–Thisisaby-productofthesmallerincrementalchanges,butisakeyenablerofavailability.

4) Movefromprotectingjuston-premisestosomedegreeofoff-premisethinking–Sure,youarestillprotectingwhat’son-prem,butuseofthecloud,IaaS,SaaS,etc.areallpartoftheavailabilityplan.

5) Animprovedcost-to-benefitratio–Whilethelastoption(RaaS)probablycomesacrossasthemostexpensive(inalistthatissupposedtobegettinglesscostlyaswego),considerwhatthecostwouldbetoachievethisusingsimplebackupandrestore…andthenaddonthecostthelackofavailabilityofbackupandrestorebrings.Eventhoughthecheckwritteneachmonthisfarmorethanthecostofafewbackuptapes,thisoptionguaranteesyouarerecoverableinaveryshorttimeframe.

Allofthisputsussquarelywherewearetoday–thinkingaboutcontinualrecoveryprocessesutilizingbothon-premandcloud-basedinfrastructurestogetherinthemostcost-effectivewaytoempowertrueavailability.

Whileyouarelikelyinvestinginsomeofthetechnologiesthatmakeupamoderndatacenter,youprobablystillfindyourbackupandrecoveryeffortssomewhereinthemiddleoftheevolutiontoavailability.

So,howdoyoumakethetransitionfrombackuptoavailability?

Theanswerliesinfirstdefiningthedifferencebetweenthem.

Backupvs.Availability

Everyone,atsomepoint,stillperformsbackups.Theymightgobyanothername,suchassnapshotsorreplication.Butattheircore,theyservethesamepurpose.

Regardlessofwhereyouareinthestrategyortechnologyspectrumspreviouslylisted,whenitcomesdowntoit,youstillfocus,atsomelevel,onbackups.

Itmayseemthatavailabilityismerelyanadvancedformofbackupandrecovery(probablybecauseyou’rethinkingaboutitintermsofbackups).Inreality,nothingcouldbefartherfromthetruth.

Yousee,backups,attheircore,defineadatasetthat’sbeingprotectedandcanberecovered,andthenhaveyouworkforwardtoseeifwhatyou’vebackedupwillactuallygetyou

operational.Forexample,backupsofentireserversandsystemstatesinWindowsmaystillrequireanadditionalrecoverystep,suchasrestoringandbringingdatabasesinExchangeorSQLServerintoaconsistentstate.

Soasinglebackupdoesn’tnecessarilyequatetoarecoveredapplication,server,orenvironment.Ontheflipside,availabilitydemandsthatyoubeginwithwhatneedstobekeptrunningandworkbackwardstoidentifybackuptechnologiesthatmeettheneedandthebackupandrecoverystrategythatsupportstheendgoal.

So,justhowfarapartisyourbackupstrategyfromavailability?

Thereissomedifferencethatexistsbetweentherequirementsyourbusinesshasaroundkeepingsystemsandapplicationsavailable,andthebackup/recoverycapabilitiesyoucurrentlycanprovide.YoulikelyhaveidentifiedapplicationsthathavespecificSLAs,andyoualsoknowhowquicklyyourbackupsolutioncanrecoversaidsystem.Thenyoumultiplythatsamescenariobythenumberofcriticalapplicationsyouneedtorecover.Morelikelythannot,youcanrecoversomeoftheminthetimeallowed,butnotnecessarilyallofthem.

Othersofyoumaynothavedefinedtheavailabilityrequirements,soyoudon’tknowquitehowlargethegapbetweenbackupandavailabilityreallyis.

82%oforganizationsidentifythemselvesashavingagapbetweenbackupsandavailabilityintheAvailabilityreport.Ifyou’renotsure,youprobablyfitintothatgroup.

Solet’sgiveavailabilitysomelevelofdefinition.

Becauseyou’realreadyfamiliarwithbackups,let’sborrowsomecommontermsfrombackupsyou’refamiliarwith–after

all,evenwithavailability,youwillstillworkbackwardsallthewaytoabackupofsomekindatsomepointintheprocess.

Availabilityitselfisanobjective–agoaltobeupandrunningasclosetoalwaysaspossible.Backups,too,haveanumberofobjectivesthatspecifyoperatingparametersforyourbackups.Twospecificbackupsobjectivescanbeusedtohelpdefineavailability:RecoveryTimeObjectiveandRecoveryPointObjective.

RecoveryTimeObjective(RTO)istheamountoftimeallowedforrecoverytotakeplace.Thisusuallyisdefinedonaper-applicationorper-serverbasis,aseachapplication,system,ordatasethasitsownlevelofcriticalitytotheorganization.

RecoveryPointObjective(RPO)isthepointintimetherecoveryshouldbringthebusinessbackto.Or,inotherwords,theamountofdata(intermsoftime)theorganizationiswillingtolose.

So,iftheRTOisanhourandtheRPOis4hoursforagivenapplication,TheRTOdictatesyouhaveanhourtorecoverthegivendataset,whereastheRPOdictatestheITorganizationneedstobeplanningforbackupsofthatdatasetevery4hours,ataminimum.

So,whatshouldthevaluesbefortrueavailability?

Whilethereisnoindustry-definedvalue,agoodruleofthumbistoconsiderbothanRTOandRPOofjust15minutes.Iknow,Iknow…soundslikeI’macrazyperson,right?Butwe’retalkingaboutapplicationssoimportanttotheorganizationtheyneedtobetrulyavailable.ToparaphraseMiracleMax,“There'sabigdifferencebetweenmostlyavailableandavailable.Mostlyavailableisslightlydead.”

NoITproeverwantstotelltheexecutiveteamtheircriticalappis“slightlydead.”Byusingthe15minuteRTO/RPOvalues,you’dbeupandrunningin15minutesonlyhavinglost15

minutesofdata.That’saprettytightwindow,butyouneedtoconsidereachapplicationinyourenvironment,itscriticalitytothebusiness,andhowlongoperationscanreallygowithoutit.

Availabilityhasbeenaroundforyears,butthecostofachievinga15-minuteRTO/RPOhasbeentoohightomakeitcost-effective.

Regardlessofthespecificvaluesyoucomeupwith,thegoalshouldbetohaveverysmallvaluestoensurebothoperationsareupveryquicklyandverylittledatahasbeenlost.And,remember,ashortRTO/RPOispossible(moreonthatlater).

So,howdoyouachieveavailability?Isitjustbybuyingsomenewtechnology?Comingupwithanewstrategy?Orbydoingsomethingdifferent,instead?

AchievingAvailabilityHopefullybynow,yourecognizetheimportanceofgettingyourorganizationtoahighdegreeofavailability.Thesheernumberofidentifiablemissioncriticalapplicationsandsystemswithinyourorganizationalonewoulddictatehowimportantavailabilitytrulyis.So,howmanyisthat?Whatpercentageofyourapplicationandsystemworkloadswouldyouconsidermissioncriticaltotheorganization?

Giventhegrowthintheneedforavailability,woulditsurpriseyouatallthatthenumberofmissioncriticalapplicationsandsystemsinyourorganizationswillonlygrow,increasingtheneedforavailability?Thetimetogetthisrightisnow.

AccordingtoVeeam’sAvailabilityreport,almosthalfofallworkloadsareconsideredtobe“mission-critical”today.Thannumberwillincreaseby15%overthenexttwoyears.

Thereallygoodnewshereisyou’renolongerconstrainedbytechnology.TheabilityexiststodaytomeetverytightRTOsandRPOsbysimplytakingadvantageoftechnologiesthatarepartofamoderndatacenterstrategy.Now,itmaycostyoumoretoimplement,butgiventheimportanceofagivenapplication,thatcostmaybejustified.

Sincethetechnologyexists,achievingavailabilityisalotmoreaboutanexecutionstrategyandchoosingtherighttechnologytogetthere.Hereare5stepstohelpyoumakeprogresstowardachievingavailability.

1) Understandthebusinessrequirements–WhileI’vediscussedusingbackupobjectives,don’tstartthere(thosewillcomeinamoment);beginwithdefiningwhatthebusinessneedstooperate.Listouttheapplicationsthatarebothinternallyandcustomerfacingandcanbethoughtofasmissioncritical.

2) EstablishtiersofCriticality–whileeveryapplicationandsysteminthecurrentlistwillbe“critical”,weallknowyoucanweaseloutdifferenttiersofimportancefrommanagementifpressedhardenough.Afterall,ifyouwereinasituationwhereyoucouldonlygetoneofthemissioncriticalsystemsup,I’msuretheexecutiveteamwouldbeabletotellyouwhichonetheywant(andthen,ofcourse,they’dfireyouforonlybeingabletorecoverone…butIdigress).Thetiersof

importancemayverywellbealistofapplicationsindescendingorderofpriority,oryoumaybeabletoputthemingroupsbasedonequalimportance.

3) Developper-applicationrecoveryobjectives–Here’swhereyouputsomeactualnumberstoquantifywhatitmeanstobebothcriticalandatagiventier.Askthequestion“Howlongcanwebewithoutthisapplication,andhowmuchdatacanweaffordtolose?”todevelopRTOsandRPOs.Anyanswer,includingtheseeminglyunreasonable“Noneandnone”isanacceptableanswer.Why?Becauseitgivesyouagoaltohit(thatiswhythey’recalledobjectives)aswellasastartingpointwithwhichtobeginbuildinganavailabilitystrategy.

4) Buildastrategyaroundavailabletechnology–So,let’ssayyourERPsystemneedstohitthat15-minuteRTO/RPO.Howareyougoingtodothat?Lookatwhat’savailable(andIdon’tmeanjustwhatyouhavetoday,butwhatisavailableintheindustry)tocreateamethodbywhichyoucanachievetheobjectives.Witha15-minuteRPO,you’remostlikelygoingtoneedtolookatimage-basedbackupsofblockchangesreplicatedtoamirroredvirtualserver.Ifyou’relookingtoprotectagainstnaturaldisasters,thatserver’slocationwouldneedtoberemote.The15-minuteRTOmeanswhateverredundantinfrastructureyouhaveinplacewillneedtobelyinginwait,readytobefailedovertoatamoment’snotice.It’sthiskindofthinkingthat’sjustthestartofplanningyourstrategy.

5) Test,test,test–Thisistheoften-overlooked,mostcriticalstep.Imean,c’mon–we’retalkingaboutyour

mostcriticalapplicationsherewitha15-minutemarginoferror!Youneedtobecontinuously(notperiodically…continuously)testingeachandeverybackupthatisrecoveredtothealternatesitetoensure–withoutadoubt–thatwhenneeded,theapplicationwillrecover.

Somewherebetweensteps4and5is,ofcourse,implementingthetechnology.Ipurposelyleftthatout,asit’smoreatacticalaspect,ratherthanastrategicone.

Youcan’tjustbuysomething,switchitonand…BAM–Availability!It’sgoingtotakecarefulassessmentandplanningtocraftastrategyandexecutionplanthatwillensurethehighestlevelsofavailabilitypossible.

BeforeIendthissection,Iwanttocoverafewconsiderationsthatareamixoffinalthoughtsandnotesthatdidn’treallyfitneatlyanywhereelseinthebook,inanefforttogiveyouthebestchanceofmakingavailabilityhappen.

Availability-enablingconsiderations

• TheCloudandthe3-2-1rule–Acommonruleofthumbforbackupsistohave3copieson2differentmediatypeswith1ofthecopiesstoredoffsite.Thecloudprovidesanextremelycost-effectivemeanstoveryquicklymoveabacked-updataset(whetheritbefiles,aVMimage,etc.)offsite.Remember,disasterstakemanyforms,includingthelossoflocation,inwhichcasehavinganoffsitecopywillnotonlybehelpful,butnecessary.

• Goingoffsitedoesn’tguaranteeavailability–Whilehavinganoffsiteoption(whetherpublicorprivatecloud)helpsfromaDRandbackupperspective,

rememberthatoptionisstillonlyasgoodasyourcloudprovider.Besureyouknowwhoyou’resigningupwith,andgetboththeirSLAhistoryandaremediationplanshouldsomethinghappen.

• Backupsstillhavearole–Remember,availabilityisagoal;backups–eveniftheychangetheirspotsabitmovingfromfile-basedtoVMimage-based–arestillastrategicpartofthetacticalexecutionoftheavailabilitystrategy.

• Evenlocalstorage-basedsnapshotscanhelp–Thesebackupshavelessimpactonproductionsystemsandcanbecreatedfrequently.Whiletheyhavenorealplaceinthe3-2-1rule(astheysitinthesameplaceyourVMsare),theystillcanhelpbringaboutavailability,dependingonthetypeoffailure.

MakingAvailabilityaRealityIfthedemandtobealwaysonislowforyourorganization,don’tkidyourself–it’scoming.Eventually,everyorganizationwillfindsomelevelofneedforavailability,andtreatingthismatterinaproactivefashionnowwillhelpensureyoursuccess.

Today,thereisanabundanceoftechnologyabletosupporttheavailabilityofmissioncriticalapplicationsandsystems.Byimplementingsomeorallofthemoderndatacenterinitiatives,you’llalsobeputtinginplacethepiecesnecessarytobuildaproperavailabilitystrategythattakesadvantageofbackupswhilenotmakingthemthefocus.

Byidentifyingthebusinessrequirementsaroundavailability,establishingrelevantrecoveryobjectives,andworkingbackwardstotakeadvantageofthosepartsofthemodern

datacenteryou’veimplemented,you’llbewellonyourwaytoachievingastateofavailability.

Don’ttakeitallonatonce;startwithsomething…butstartnow.