Lenovo ThinkServer RS140 - Raid for Your Server

•RAID1:mirroringwithoutparityorstriping
RAID1usesmirroringsothatdatawrittentoonedriveissimultaneouslywrittentoanotherdrive.Thisis
goodforsmalldatabasesorotherapplicationsthatrequiresmallcapacitybutcompletedataredundancy.
RAID1providesfaulttolerancefromdiskerrorsorfailuresandcontinuestooperateaslongasatleast
onedriveinthemirroredsetisfunctioning.Withappropriateoperatingsystemsupport,therecanbe
increasedreadperformanceandonlyaminimalwriteperformancereduction.
RAID1requiresaminimumnumberoftwoharddiskdrives.
•RAID5:block-levelstripingwithdistributedparity
RAID5usesdiskstripingandparitydataacrossalldrives(distributedparity)toprovidehighdata
throughput,especiallyforsmallrandomaccess.RAID5distributesparityalongwiththedataandrequires
alldrivesbutonetobepresenttooperate;drivefailurerequiresreplacement,butthearrayisnot
destroyedbyasingledrivefailure.Upondrivefailure,anysubsequentreadoperationscanbecalculated
fromthedistributedparitysothatthedrivefailureismaskedfromtheenduser.Thearraywillhavedata
lossintheeventofaseconddrivefailureandisvulnerableuntilthedatathatwasonthefailingdriveis
rebuiltontoareplacementdrive.Asingledrivefailureinthesetwillresultinreducedperformanceof
theentiresetuntilthefailingdrivehasbeenreplacedandrebuilt.
RAID5requiresaminimumnumberofthreeharddiskdrives.
•RAID10:acombinationofRAID0andRAID1
RAID10consistsofstripeddataacrossmirroredspans.ARAID10drivegroupisaspanneddrive
groupthatcreatesastripedsetfromaseriesofmirroreddrives.RAID10allowsamaximumofeight
spans.YoumustuseanevennumberofdrivesineachRAIDvirtualdriveinthespan.TheRAID1
virtualdrivesmusthavethesamestripesize.RAID10provideshighdatathroughputandcompletedata
redundancybutusesalargernumberofspans.
RAID10requiresaminimumnumberoffourharddiskdrives.
FordetailedinformationaboutRAID,referto“IntroductiontoRAID”intheMegaRAIDSASSoftwareUser
GuideonthedocumentationDVDthatcomeswithyourserver.
RAIDforyourserver
ThistopicprovidesinformationabouttheRAIDsupportedbyyourserver.
Note:BeforeconfiguringRAIDforyourserver,ensurethatyouuseharddiskdrivesthatareofthesametype
(SATAorSAS)andhavethesamecapacitywithinasingleRAIDarray.
YourserversupportsthefollowingtwotypesofRAIDconfigurations:
•OnboardSATAsoftwareRAIDconfigurationusingtheIntelRapidStorageTechnologyenterprise
program
TheonboardSATAsoftwareRAIDcontrollerisintegratedontheIntelC226chiponthesystemboard.If
yourserverhasSATAharddiskdrivesthatareconnectedtothesystemboard,youcanusetheIntelRapid
StorageTechnologyenterpriseprogramtoconfigureRAID.Bydefault,yourserversupportsonboardSATA
softwareRAIDlevels0,1,5,and10.TheonboardRAIDisasoftwareRAIDinsteadofahardwareRAID.
Fordetailedinformation,see“ConfiguringthesystemBIOStoenableonboardSATARAIDfunctionality”
onpage49.
48ThinkServerRS140UserGuideandHardwareMaintenanceManual