1

APPLICATIONNOTE

FAQ: Vicom Data Migration Services

Asaproviderofturnkeydatamigrationservices,Vicomisoftenaskedhowourapproachcompareswithalternativemethods1beingconsideredbycustomers.

Amongthecomparisonsrequested,hostorserver­basedmigrationperformedbyin‐houseITstaffsarethemostcommonbecausethemethodisfamiliaranditoffersperceivedcostadvantages.However,asthesizeandcomplexityofSANshavegrownand24x7operationshavebecomemoreprevalent,companiesareturningincreasinglytooutsourcingandspecializedtoolstohelpminimizethedisruptiveimpactmigrationscanhaveonbusinessoperations.

Intheirsearchfornewsolutions,customersaskforinformationaboutmigrationmethods,speeds,projectduration,requiredserverandsystemoutage,anddataintegrity.Theirquestionsinclude:

• HowdoesVicom’stotal,turnkeyapproachcomparewithin­house,host­basedmigrations?

• WhataretheprimaryadvantagesofVicom’smigrationapproach?

• Whoareyourcustomers?

• HowdoVicom’sMaxSpeedandContinuousmigrationmethodscomparein:

- Migrationspeed?- Systemavailability?- Timetocompletion?

• HowdoesVicomverifythedataintegrityofitsmigrations?

Q: How does Vicom’s approach compare with in-house, host-based migrations?

VicomTurnkeyApproachtoDataMigrations

VicomSystem’sDMS(DataMigrationService)isaturnkeyserviceinwhichanexperiencedmigrationspecialistmanagestheentiredatamigrationproject,start‐to‐finish—frominitialplanningtoservercutover.Moreover,everyDMSmigrationisbackedbyamoney‐backguaranteeofon‐timecompletion.Thisguaranteeismadepossibleby:

• Apurpose‐built,migrationappliancethatmovesdataindependentofserversandstoragesystems,atspeedsofupto1terabyteperhour.

1Foranextensivesurveyandcomparisonofothermigrationmethods,seetheVicomSystemswhitepaper,“NewWatchwordsforNetworkedStorageMigrations,”November2007.

2

Theapplianceiscapableofmigratingdatawhileserversareofflineoronline.

• SANvirtualizationtechnologythatsimplifiessystemandstorageconnectionbyeliminatingincompatibilitiesandtheneedfordriverandOSupdateinstallationsonhostsystems,includinglegacysystems.

• Automateddiscoveryandmigrationmanagementwhichreducesthelaborandhumanerrorassociatedwithcomplexmigrations.

• Aprovenmigrationprocessforplanning,discovery,migrationmanagement,andverificationthathasbeendevelopedinthecourseofdeliveringofover500enterprisedatamigrations.

• Anon‐intrusiveandsecuremigrationmethod,performedwithouttheneedforsoftwareagentsorsystemmodifications,“musts”formanysecurity‐sensitivefinancialandgovernmentapplications.

• Experiencedmigrationspecialistswhooverseetheprojectfromstarttofinish.

Vicom’sprincipalobjectiveistodeliveryaproblem‐free,on‐timemigrationatanaffordableprice.WhileVicomreliesmainlyonitsSANbasedhardwareDataMigrationAppliancetomigratedatainfast,offlinemodeorcontinuous‐accessonlinemode,wealsousehost‐basedsoftwaretoolsasneededtoperformsupplementalservices,suchasLUNconsolidationandNASmigrations.Thissolution‐orientedapproachenablesVicomtohandledatamigrationsmoreeffectivelythananyotherserviceprovidersinthestorageindustry.

Figure1.VicomAppliance‐BasedOfflineandOnlineMigration

In­House,Host­BasedMigrations

Host‐basedmigrationisafrequentchoiceofITmanagers,especiallyforsmallerdatamigrations.Becauseexistingdataiscopiedorreplicatedbetweentheoldstorageplatformandanewerone,anyofseveralmethodsofdatareplicationemployingserver‐processingpowermaybeused.Typically,dataismigratedbetweenoldandnewstoragesystemsbymirroringdatavolumeswithastoragemanagementapplicationorcopyingfilesusingnativeOStools.Insomeinstances,third‐partydatamigrationapplicationsarealsoused.

3

OneoftheprincipalreasonsITmanagersselectin‐house,host‐migrationmethodsislowerout‐of‐pocketcosts,particularlywhennativeOSutilitiesareused,sinceadditionalhardwareandsoftwarepurchasesarenotrequired.Relianceonexistingutilitiesandsystemsoftwarealsoeliminatestheneedfornewapplicationqualificationandtraining.Whenused,mirroringorfile‐copymethodsalsoenablecontinuousserveraccesstothesource(old)storagewhiledataismigratedtothenew(target)storageinthebackground.Fromaprojectmanagementstandpoint,datasetsmaybemovedindividuallyandreorganizedatthesametime—agoodoptionwhenthemigrationisrelativelysimpleandsmallinscale.

Bycomparison,specializeddatamigrationsoftwareapplicationsareoftenpreferabletonativesystemutilitiesbecausededicatedtoolscanprovidebetter,moretailoredcontroloverthemigrationprocess.Whenmigrationsoftwareisconsidered,automationanddiscoveryshouldbeamongtheprincipalreasonsforitsselection.Ataminimum,thesoftwareshouldincludemechanismsforSANdiscovery,migrationplanning,andactivemigrationmanagementandcontrols.Itshouldalsobenotedthathost‐basedmigrationsoftwaretoolsaretypicallylimitedintheirrangeofplatformcompatibilitybecausetheymustbeportedtovariousoperatingsystems.WhilethesetoolsmayworkwithcurrentOSplatforms,legacysystemsoftenpresentupgradeanddriverincompatibilityissues.

Q: What are the primary advantages of Vicom’s

migration approach?

Whilehost‐basedmigrationprovidessomeadvantages,manyofthesetendtobeoffsetbyimplementationandoperatingconsiderations,especiallyasthescaleofmigrationsandnumberofserverplatformsincrease.Inaddition,althoughout‐of‐pocketexpensesofin‐househost‐basedmigrationsmayappearsmall,thecostofITresourcescanaddupquickly.Byundertakingamigrationproject,ITassumesallresponsibilityandriskforon‐timeprojectdelivery.Moreover,latemigrationdeliveriescanalsoaddsignificantlytoleasedstoragecostsandadverselyaffectbusinessoperations.Accordingtoa2005surveyofover200ITmanagersbytheEnterpriseStorageGroupandInfoStorMagazine,83percentofinternalmigrationprojectsexceedplannedstafftime,61percentrequiremoredowntimethanexpected,and54percentareoverbudget.VicomAdvantages:ExperienceandTechnology

Vicom’stechnology,automation,provenprocesses,andspecialist‐backedserviceseliminatemuchofthecomplexityandlaborassociatedwith

Server

SAN

Figure2.Host‐BasedMigration

4

migrations.Vicomdeliversdatamigrationsfaster,withfewerproblems,andzerooperatingrisk.And,withtheexceptionofcustomizedmigrations,Vicomalsoprovidesamoney‐backguaranteeforon‐timecompletionofeachofitsmigrations.

AdvantagesofVicommigrationsoverin‐house,host‐basedmethodsinclude:

• Automateddiscoveryandconfigurationverificationthateliminateslaborandhumanerrorassociatedwithmanualmigrationmanagement.

• SANvirtualizationtechnologythateliminatesSANcompatibilityissuesandtheneedforsoftwareanddriverinstallationonhostsystems,savingtimeandlabor.

• Afast,independentdata‐movingappliancethatmigratesdataatmuchhigherratesthanpossiblewithhost‐powereddatamigrations.Typically,theVicomapplianceinMaxSpeedmodemigratesdataat600GBto1TBperhourcomparedto100GBperhourorlessforhost‐poweredmigrations.

• Guaranteedfallbacktooriginalsystemoperationintheunlikelyeventthatissuesariseduringamigration.

• Provenmigrationprocessesdevelopedinthedeliveryofover500enterprisemigrations.

• Experiencedmigrationspecialistswhohavedeliveredmigrationsinabroadrangeofenvironments,configurations,andoperatingcircumstances.Thisincludeslegacy/mixedplatformandmixedfabricenvironments,clusteredservers,bootLUN,LUNconsolidation,andcontinuousavailabilityoperations.

• Aone‐stop,solution‐orientedmigrationservicethatnotonlyuseshighlyefficientVicommigrationappliancetechnology,software,andprocesses,butalsobest‐of‐breedthird‐partysoftwaretoolstosatisfyuniquemigrationrequirements.Ourrepertoireincludeshost‐basedmethodsandsoftware.WemigratebothSANandNASdata.WithVicom,youhaveacost‐effective,single‐vendormigrationproviderregardlessofconfigurationoroperatingneeds.

Example:LaborComparisonBetweenIn­HouseandVicomMigrations

IncomparingVicom’sapproachwithin‐housemigrationprojects,itiseasytoseewhyVicomholdsmorethana3:1advantageinlaborandtimerequired.Mostcompaniesareconfrontedwiththeneedtoperformlarge‐scaledatamigrationsonlywhenastoragetechnologyrefreshisrequired.Asaresult,mostITstaffsarerelativelyinexperiencedatdeliveringcomplexmigrations.Often,theyhaveonlybasicprocessesestablishedforplanning,coordinatingserverandstorageavailabilities,andmigratingdata.Forthesamereason,migrationtoolsandexperienceinusingthemaretheexceptionratherthantherule.Bycomparison,aVicommigrationspecialistsperformmigrationseveryweek.Provenprocessesarefollowedoneverymigration,whiletoolsandsoftwareeliminatemuchofthelaborandneedfortroubleshootingassociatedwithmanualmigrations.

5

Toshowhowthesedifferencesaffecttheimplementationandcompletionofamigrationproject,Table2comparestheestimatedlaborfora10‐terabyte/10‐server,in‐househost‐basedmigrationconfiguredforonlineoperationwiththelaborforanequivalentonlineContinuousmigrationusingaVicommigrationappliance.

Asshownbythiscomparison,thein‐house,on‐linemigrationrequiresalmostthreetimesthelaborneededforaContinousmigrationusingtheVicomappliance.Incontrast,aVicomMaxspeedofflinemigrationwouldbeabout25percentmoreefficientthantheContinuousmethod,resultingina4:1Vicomadvantage.(Note:thecomparisondoesnotincludetimespentinreplicatingdatawhileonline,whichwillberoughlythesameforhost‐basedandVicommethods.)

Amongthesevenindividualmigrationstepsshown,Vicomholdsalaboradvantageof2:1to40:1.And,whileVicomtechnologymakesabigdifference,ourexperienceshowsthatoneofthebiggesttime‐saversistheVicommigrationplanningprocess,whichisbuiltoninformationacquiredfromVicomtoolsanddocumentation.

Q: Who are your customers?

VicommigrationcustomersrunthegamutfromFortune1000tosmallandmediumenterprisesacrossarangeofindustries.Throughdirectservicesandservicepartnerships,Vicomhassuccessfullydeliveredover500datamigrationsandmovedoverfivepetabytesofdataindiverseenterpriseenvironments.Selectedcustomersarelistedbelow.ReferencesareavailableuponrequestfromVicomSystems.

Avaya Goody’sClothing ScientificLearningBloomberg Heinz SiemensBlueCross HealthFirst SiriusSatelliteCaterpillarTractor Intelsat SouthernCompanyComcast MCGHealth StateFarmInsuranceDCMA(U.S.Gov’t) Pepsico TexasLegislativeCouncil

Table 2. Labor Comparison for Host-Based vs. Vicom Appliance-Based Migration

6

DeutscheBank Prudential TorayPlasticsDialAmerica ReedBusiness TimkenEsurance RoperSt.FrancisHealth UnileverFruitoftheLoom RoyalCaribbean WellsFargo

Q: How do Vicom’s MaxSpeed and Continuous Migration methods compare in:

• Migration speed?

• System availability?

• Time to completion? Vicom’sMaxSpeedmigrationsareperformedduringplannedoutageperiodswhenserversmaybetakenoffline.Duringtheseperiods,themigrationappliancereplicatesdatafromsourcetonewstoragesystematmaximumavailableI/Obandwidths.However,undersomecircumstancessuchase‐commerce,operatingrequirementsmayseverelyrestricttheperiodinwhichhostserverscanremainoffline.Intheseinstances,itmaybemoreeffectivetouseaContinuousmigrationmethodinwhichdataismigratedinthebackgroundwhilethehostserversremainonline.Figure3illustrateshowthesetwomethodscompareinserveroutagewindowsandtimerequiredtoperformthemigrations.

Figure3.MaxSpeedvs.ContinuousMigration

7

Table1belowfurtherillustateshowthetwomethodsdifferinmigrationspeed,serveravailability,andmigrationcompletiontimes.

Timeandspeed‐wise,MaxSpeedmigrationsaremuchfasterthanContinuousalternatives,especiallyasthenumberofserversincreases.ThisisduetothespeedadvantageofVicom’smigrationapplianceandefficiencyoftheMaxSpeedmigrationmethod.Forthetypicalmid‐sizemigrationof5‐30terabytesand10‐20servers,MaxSpeedmigrationscanbecompletedabout4timesfasterthanContinuousmigrations.

InlargeSANstoragemigrations,wheretherearebusiness‐criticalandnon‐businesscriticalavailabilityrequirements,VicomusesbothMaxSpeedandContinuousmigrationmethods.Typically,Maxspeedmigrationisusedtomigratethemajorityofdataquicklyandefficiently,whileContinuousmigrationisreservedforbusiness‐criticalapplications.Thiscombinedapproachproducesacost‐effectiveresult,whilealsosatisfyinghigh‐availabilityoperatingneeds.

Q: How Does Vicom Ensure Migration Data Integrity? Toensuremigrationdataintegritywhilealsomeetingoperatingconstraints,VicomSystemsemploysamulti‐leveldataverificationmethodthathasbeenusedinover500enterprisemigrationswitha100‐percentsuccessrate.Infact,inmigratingoverfivepetabytesofdata,notasinglebyteofdatahaseverbeenlostorcorrupted.Toachievethis,Vicomemploysacombinationofdeviceandsystem‐levelverificationthatincludes:• SAN‐level,error‐correctionlogicbuiltintoVicom’smigrationappliance• SAN‐levelerror‐logging• LUNintegritychecks• Filesystemandapplicationchecks

Table1.MaxSpeedvs.ContinuousMigrationSpeeds

8

SAN­levelErrorCorrection

TheVicommigrationapplianceisdesignedforextremelyreliableSANdatareplicationatFibreChannelspeed.Inreplicatingdata,allsourcestoragedataremainsintactduringandaftermigration,providingafail‐safefallbackalternativeintheunlikelyeventofadatamigrationproblem.Throughembeddedhardwaredesign,allmigrateddataissubjectedtoerrorcheckingandsingleanddouble‐biterrorsaredetectedonthefly.Replicationalsorequiresthatdatamustbeverifiedbeforeitcanbewrittentothenewsystem.Error‐correctionandreplicationbytheVicomappliance,combinedwithhighlyreliableSCSI/FCprotocol,producestheequivalentofdirectRAID­1mirroringbetweenthesourceandnewstoragesystem.Ineffect,theVicomapplianceactsasadedicatedRAIDcontrollerthatcreatesamirroredcopyofthesourcedata—asimplerandmorereliablemethodthanhost‐basedcopymethodsofdatamigration.

SAN­levelExceptionLogging

TheVicomappliancemonitorstheentiredatamigrationandlogsanyexceptionsreportedduringtheoperation.Whenreported,abnormallevelsofexceptionhandlingmayindicatepotentialdataintegrityproblems.Vicomstandardprocedurescallformigrationspecialiststoreviewexceptionlogs,and,ifproblemsareidentified,torepeatthemigrationfortheproblematicLUN.LUNIntegrityChecks

Followingmigration,thefirstandlastdatablocksofeachnewLUNarecomparedwithdatablocksinthesourceLUN.FileSystemandApplicationChecks

Thefinalverificationstepfollowingmigrationconsistsof100‐percentfilesystemconsistencycheck(FSCK)ofdatavolumesand100‐percentapplicationlaunchtest.Ingeneral,customerITstaffshavepreferredtoperformthissetoftestsasameansoffirst‐handmigrationverification,aidedbytheVicommigrationspecialistasrequired.

Figure4.DataIntegrityChecks

9

Asmentionedatthebeginningofthisnote,Vicomhasmigratedoverfivepetabyteswithoutaninstanceoflossorcorruptionofasinglebyteofdata.Thisincludesthemigrationofover100,000LUNs.Basedonactualperformance,webelievetheefficacyofbothVicommigrationtechnologyanddata

www.vicom.com

Copyright 2009, Vicom Systems, Inc. All rights reserved. Vicom Systems, Vicom DMS, and MaxSpeed are trademarks of Vicom Systems, Inc. Other company and product names mentioned herein are trademarks of their respective companies. December 2008. V010809.