Synology RAID F1: Rethinking RAID in all-Flash Environments

Synology Raid F1 is an algorithm developed by Synology that helps mitigate this risk. RAID F1 is a 1-disk resiliency based on RAID 5 ... Article SynologyRAIDF1:RethinkingRAIDinall-FlashEnvironments By InsightEditor / 11Jan2017 / Topics: Hardware Storage Thestandardizationofflashstoragehasbroughtwithithugeleapsinstorageperformance,energyefficiency,anddevicesize.SynologyremainsdedicatedtoprovidingadvancedsoftwareRedundantArrayofIndependentDisks(RAID)solutionsthatmaximizereliabilitywhileadaptingtotheeverchangingstoragelandscape. SolidStateDrivesandtheFutureofStorage Costpergigabytehasrecentlyplummetedinflashmemory,makingpreviouslycostprohibitiveall-flashstoragearraysanewoptionforsmallbusinesses.Ascompaniesbegintorelyonstoragepoolsmadeentirelyofflashmemory,softwaresolutionsrunningonappliancesthatsupportflashdevicesmustalsoadapt.Currently,moststoragedevicestreatSolidStateDrives(SSDs)likeHardDiskDrives(HDDs),despitesomecrucialdifferencesinstructureandoperation.TheimportantdifferencehereisthatunlikeHDDs,SSDshaveadefinedlimittothenumberofreadandwriteoperationstheycanperformintheirlifetime. HardDiskFailure:RedundancyisKing AnygroupofHDDswrittentowithmirroredorsimilaramountsofdata(seeninstoragedevicesusingclassicRAIDconfigurations)willexperiencesporadicfailuresofmemberdisks.Thiscanoccurfromenvironmentalfactorslikevibration,moisturebuild-up,ordustcontamination.BecauseHDDsrelyonmovingpartstoreadandwritedata,evenwhenenvironmentalfactorsareaccountedfor,manufacturingdefectsinthesemovingpartscancauseprematurefailureaswell.ThesefactorscombinedmakeHDDfailuresmorerandom,andverydifficulttoaccuratelypredict.SincethelifespanofanindividualHDDinaRAIDgroupcannotbedetermined,itmakesthemostsensetotreatallmemberdisksasequallylikelytofail.InclassicRAIDdeployments,dataiswritteninequalamountstoallmemberdisks.DiskredundancyinaRAID1,5,6,etc.expectsarandom,single(sometimesmultiple)drivefailure,andhelpsprotectagainstdatalossinthosescenarios. CurrentsoftwareRAIDsolutionsworkwellforHDDs,buttransitioningtoSSDsprovidesanewchallengefordataprotectionsolutions.WiththeknowledgethatSSDshaveasetnumberofreadandwriteoperationsintheirlifespan,writingdataevenlyandconcurrentlytoallSSDsinanarraycouldresultinallofthedrives“expiring”atthesametime.ThereisnoRAIDtechnologyavailablethatcouldsurviveasimultaneousfailureofeverymemberdisk,thisscenariowouldbeadatalossdisaster.So,howbesttoapproachthisnewissuefacingallflasharrays? SynologyRAIDF1 SynologyRaidF1isanalgorithmdevelopedbySynologythathelpsmitigatethisrisk.RAIDF1isa1-diskresiliencybasedonRAID5concepts.RAID5providesdataredundancyby“striping”dataandparitybits(additionaldatausedforrecoveryoperations)acrossthreeormorememberdisks.EachdriveinaRAID5groupstoressmallpiecesofdataaboutwhatinformationisontheotherdrivesinthatarray.Ifasingledrivefails,thedata“about”thefaileddrivestoredontheotherdisksisusedtorecreatetheinformationfromthefaileddrivewhenanotherisaddedtothegroup. RAIDF1differsfromRAID5byselectingoneSSDinthearrayfordistributionofadditionalparitybits,effectivelywritingmoredatatooneSSDthantoothersinthegroup.WritingmoredatatoasingleSSDinagroupofSSDsallowsforasingledisktocompleteitsestimatedlifecyclebeforeanyothersinthearray.Thisprovidesasingle,predictablefailurepoint,whichiswithinthefaulttoleranceofthearray.ThechosenSSDinthesecasescouldthenberemovedwhenitnearstheendofitslifespan,andreplacedwithanewdrive.RAIDF1willthenselectanewSSDonwhichtowritethoseextraparityblocks,againchangingtheexpectedexpirationrateofthenewlyselected,andpreventingtotalarrayfailureduetoconcurrentSSDexpiration. SynologyFS3017:EnterpriseHardwarewithouttheSecondMortgage RAIDF1isavailableontheSynologyFS3017,anallflashstoragecontrollerwithdualXeonsixcoreprocessors,64GBofDDR4ECCRAM(expandableto512GB),builtin10GbE(withsupportfor25GbEand40GbE),andcomesequippedwiththelatestversionofDSM,Synology’sawardwinningNASoperatingsystem. Unlocknewapproachestoproductivity.Whileyoumaketheleaptoremotework,we’llprovideguidance,solutionsandservicestomakethetransitioneasier. Recentarticles Article MoreThanJustVideoGames—HowEsportsareRedefiningAcademicsAccordingtoIndustryproJoeMcAllister Article HowJamfHelpsOrganizationsSucceedWithApple TechJournal TrendingTech:SolutionsforHybridWorkplaces,DataStorageandSecurity Allkeywordcategories: Article Hardware Storage Synology Relatedposts Article MoreThanJustVideoGames—HowEsportsareRedefiningAcademicsAccordingtoIndustryproJoeMcAllister Article HowJamfHelpsOrganizationsSucceedWithApple TechJournal TrendingTech:SolutionsforHybridWorkplaces,DataStorageandSecurity Solutionbrief RecoverYourDatainHoursWithIBMCyberVault