What is the difference between RAID 5, RAID 5 plus a Hot ...

Hot spare is a drive that acts as a stand by drive in RAID 1, RAID 5 or RAID 6 volume. It is fully functional drive that contains no data ... AllcommunityThiscategoryKnowledgebaseUsers cancel Turnonsuggestions Auto-suggesthelpsyouquicklynarrowdownyoursearchresultsbysuggestingpossiblematchesasyoutype. Showingresultsfor  Searchinsteadfor  Didyoumean:  WhatisthedifferencebetweenRAID5,RAID5plusaHotSpareandRAID6? Ratethisarticle: 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 100%helpful (2/2) Options ArticleHistory SubscribetoRSSFeed Bookmark Subscribe PrinterFriendlyPage ReportInappropriateContent Question   WhatisthedifferencebetweenRAID5,RAID5plusaHotSpareandRAID6?   Answer   TheRAIDcombinestwoormorephysicaldrivesintoalogicalunitpresentedasasingleharddrivetotheoperatingsystem.TherearecurrentlysixbasicRAIDlevels:RAID0,RAID1,RAID0+1,RAID1+0,RAID3,RAID4,RAID5andRAID6. ThescopeofthisarticleistoprovidebasicinformationforthelevelsRAID5andRAID6andtocomparethemfrompointofviewofperformanceandsecurity.   Hotspare isadrivethatactsasastandbydriveinRAID1,RAID5orRAID6volume.Itisfullyfunctionaldrivethatcontainsnodataandisnotusedduringnormaloperation.Ifadrivefromthevolumefails,thecontrollerreconstructsthedatafromthefaileddrivetothehotsparedrive. A RAID5 arrayisdesignedtoprotectagainstthefailureofasinglediskwithinthearray.BecauseofthewaythatRAID5works,thetotalcapacityofonediskislosttooverhead.If,forexample,aRAID5arraycontainedfive10TBdisks,thenthearray’susablecapacitywouldbe40TB. A RAID5(withHotSparedisk) arraycanbeconfiguredtotreatoneofthedisksasahotspare.Thenoneofthedisksisreservedasareplacementintheeventthatadiskfails.Fortheaboveexamplewithfive10TBdisks,thiswoulddecreasetheexamplearray’susablecapacityto30TB. A RAID6 arrayisdesignedtoprotectagainsttwosimultaneousdiskfailures.However,thepriceforthisextraprotectionisthattwodisks'worthofcapacityislosttooverhead.Assuch,aRAID6arraymadeupoffive10TBdiskswouldhaveausablecapacityof30TBbecause20TBislosttooverhead. The performance duringNormalOperationismeasuredinIOPS(Input/outputoperationspersecond)andasasumforallthedisks(excludingtheHotSparesanddecreasedforwritingparitydata)inthearray. Asaruleofthethumb,thehighertheoverheadassociatedwithwritingparitydata(intheaboveexampleRAID5withHotSparecausesthesameoverheadlikeRAID6)thelowertheIOPS. ThereasonforimplementingRAIDarraysisto securethedata.Thelevelof protection doesnotdirectlycorrelatewiththeoverhead.FromtheaboveexamplebothRAID5withHotSpareandRAID6havesamecapacity,butofferdifferentlevelofprotection.IncaseoffailureofRAID5arraywithHotSpare,theHotSpareisactivatedandtherebuildprocessstartimmediately. Thesystemcanrecoverfromasinglediskfailureandduringtherecovery,processisvulnerabletoseconddiskfailure. Therefore,RAID5andRAID5withHotSparediskofferthesamelevelofprotection–singlediskfailure.  Incontrast,ifadiskfailsatRAID6array,therecoverywillstartonlyafterthefaultydiskisreplacedmanually. However,ifduringtherecoveryprocessseconddiskfails,theRAID6arraywillstayfunctional. Share Versionhistory Revision#: 4of4 Lastupdate: ‎05-20-2021 10:09AM Updatedby: Central_Support   ViewArticleHistory Labels(5) Labels: bt_faq divar_ip kb-article seo vs Contributors Galina Central_Support Ratethisarticle: 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 (1) Stilllookingforsomething? Search Iconsearch Iconclose TopResults SeeallresultsIconforward-rightIconwarning Icon--AD-black-48x48Icon--address-consumer-data-black-48x48Icon--appointment-black-48x48Icon--back-left-black-48x48Icon--calendar-black-48x48Icon--center-alignedIcon--Checkbox-checkIcon--clock-black-48x48Icon--close-black-48x48Icon--compare-black-48x48Icon--confirmation-black-48x48Icon--dealer-details-black-48x48Icon--delete-black-48x48Icon--delivery-black-48x48Icon--down-black-48x48Icon--download-black-48x48Ic-OverlayAlertIcon--externallink-black-48x48Icon-Filledforward-right_adjustedIcon--grid-view-black-48x48IC_gd_Check-Circle170821_Icons_Community170823_Bosch_Icons170823_Bosch_Icons170821_Icons_CommunityIC-logout170821_Icons_Community170825_Bosch_Icons170821_Icons_CommunityIC-shopping-cart2170821_Icons_CommunityIC-upIC_UserIcon--imageIcon--info-i-black-48x48Icon--left-alignedIcon--Less-minimize-black-48x48Icon-FilledIcon--List-Check-grennIcon--List-Check-blackIcon--List-Cross-blackIcon--list-view-mobile-black-48x48Icon--list-view-black-48x48Icon--More-Maximize-black-48x48Icon--my-product-black-48x48Icon--newsletter-black-48x48Icon--payment-black-48x48Icon--print-black-48x48Icon--promotion-black-48x48Icon--registration-black-48x48Icon--Reset-black-48x48Icon--right-alignedshare-circle1Icon--share-black-48x48Icon--shopping-bag-black-48x48Icon-shopping-cartIcon--start-play-black-48x48Icon--store-locator-black-48x48Ic-OverlayAlertIcon--summary-black-48x48tumblrIcon-FilledvineIc-OverlayAlertwhishlist