Enterprise Solid State DrivesEnterprise Solid State Drives

(c) 2010 Damir Lukic

Flash drive vs. Rotational

Enterprise Enterprise Solid State DriveSolid State Drive

new (old) technologynew (old) technology~0 ms data access~0 ms data accessperformance $/IOPSperformance $/IOPS

FC/SATA 7.2/10/15krpmFC/SATA 7.2/10/15krpm

existing technology, widely acceptedexisting technology, widely acceptedhigh latency data accesshigh latency data accesscapacity $/GBcapacity $/GB

Enterprise SSD Enterprise SSD –– Inside lookInside look

Enterprise SSD componentsEnterprise SSD components ::

-- dual port FC interfacedual port FC interface-- control logic + multiplecontrol logic + multiple paralparal lleell IO IO channelschannels-- DDR SDRAM cache DDR SDRAM cache with battery backupwith battery backup-- SLC NANDSLC NAND FlashFlash

Enterprise SSD Enterprise SSD –– Technology historyTechnology history

•• SSD technology dates back to 1950SSD technology dates back to 1950

–– Core memoryCore memory

–– Card Capacitor Read Only Store (CCROS)Card Capacitor Read Only Store (CCROS)

–– development stopped due to high costsdevelopment stopped due to high costs

•• FlashFlash--based SSD is rebased SSD is re--introduced in introduced in

1995 (M1995 (M--Systems, now Systems, now SanDiskSanDisk))

•• SLC SLC –– singlesingle --level celllevel cell– speed– relatively low capacity– enhanced wearability (100.000 erase/write cycles)– enterprise class drives

•• MLC MLC –– multimulti --level celllevel cell– high capacity drives– lower wearability (1.000 - 10.000 erase/write cycles)– consumer class drives

Enterprise SSD Enterprise SSD –– Technology Technology

insightsinsights

Enterprise SSD Enterprise SSD –– Reliability Reliability

and durabilityand durability

•• Wear leveling Wear leveling –– Enterprise SSD use Enterprise SSD use

advanced wearadvanced wear--leveling algorithms leveling algorithms

that have almost no impact on that have almost no impact on

performanceperformance

•• 400GB * 100k E/W operations = 40 400GB * 100k E/W operations = 40

PB of data per drive in its lifetime!PB of data per drive in its lifetime!

Enterprise SSD Enterprise SSD –– Reliability Reliability

and durabilityand durability

•• Average Average ~150~150 years drive durability years drive durability

for 400GB drivefor 400GB drive

–– (400*10(400*1099) * 100.000 / 4 ) * 100.000 / 4 kBkB / 2000 IOPS / 365 / / 2000 IOPS / 365 /

24 / 360024 / 3600

158 yr158 yrAverage life expectancy of 400GB Average life expectancy of 400GB

Enterprise SSD driveEnterprise SSD drive

Enterprise SSD Enterprise SSD -- PerformancePerformance

•• 25002500--5000 raw IOPS5000 raw IOPS

•• >300MB/s throughput >300MB/s throughput per driveper drive

•• Enterprise SSD performance gains are visible in Enterprise SSD performance gains are visible in random random readread--miss cachemiss cache enviromentsenviroments

(block size up to 16kB)(block size up to 16kB)–– OLTPOLTP

–– highhigh--volume email systemsvolume email systems

•• readread--hit vs. readhit vs. read--miss cachemiss cache

•• shortshort--stroke stroke FC vs. FC vs. Enterprise SSDEnterprise SSD

–– 30x FC 15k drives have the same throughput as only one 30x FC 15k drives have the same throughput as only one Enterprise SSD driveEnterprise SSD drive

–– small capacity drives are used for shortsmall capacity drives are used for short--strokingstroking

Enterprise SSD Enterprise SSD -- PerformancePerformance

50005000Ent SSDEnt SSD

180180FC 15kFC 15k

120120FC 10kFC 10k

8080SATASATA

IOPSIOPSDrive typeDrive type

Enterprise SSD Enterprise SSD –– Cost savingsCost savings

•• EnergyEnergy–– electricityelectricity, , UPS sizingUPS sizing–– cooling, air conditioningcooling, air conditioning

•• SpaceSpace–– rackrack space, space, drive enclosures, drive enclosures, drive countdrive count

•• Cache memoryCache memory–– less read cache memory usedless read cache memory used–– more memory can be used for write cachemore memory can be used for write cache–– enhanced storage array performanceenhanced storage array performance

•• Enterprise storage software is often licensed per raw capacityEnterprise storage software is often licensed per raw capacity

–– less raw space leads to less spending on software licensesless raw space leads to less spending on software licenses

•• ~15x faster than typical 15k FC drives~15x faster than typical 15k FC drives

–– 15x less Enterprise SSD drives needed to achieve required perfor15x less Enterprise SSD drives needed to achieve required performancemance

Enterprise SSD Enterprise SSD -- Data safetyData safety

•• Less impact during degraded RAID operationLess impact during degraded RAID operation–– faster rebuild timesfaster rebuild times–– performance impact on RAID groups using Enterprise SSD drives isperformance impact on RAID groups using Enterprise SSD drives is less less

noticeable compared to FC/SATA drivesnoticeable compared to FC/SATA drives

•• No start/stop problems in case of power loss/power No start/stop problems in case of power loss/power offoff

–– powering off a storage array is needed during datacenter migratipowering off a storage array is needed during datacenter migrationsons–– one of the worst problems that magnetic drives have to deal withone of the worst problems that magnetic drives have to deal with are are

starts/stops after a long time of being powered onstarts/stops after a long time of being powered on–– large numbers of magnetic drives fail to initialize (Y2K examplelarge numbers of magnetic drives fail to initialize (Y2K example, customer , customer

example)example)

•• ECC ECC –– error correction codeserror correction codes–– detects 5B/512Bdetects 5B/512B

–– corrects 4B/512Bcorrects 4B/512B

EEnterprisenterprise SSD SSD –– Application Application

candidatescandidates

•• Good candidatesGood candidates– heavily utilized tablespaces

– temp files– redo logs

– indexes

– typical applications• Oracle, SQL, DB2• Exchange, Domino• Sharepoint

•• Bad candidates Bad candidates (n(notot necessarilynecessarily !)!)– sequential data (reads/writes)

• multimedia files (audio, video)• archive logs

– static documents (DOC, XLS, PPT, PDF)

EEnterprisenterprise SSDSSD –– SummarySummary

EEnterprisenterprise SSDSSD technology is ready for usetechnology is ready for use

•• better performance using fewer drivesbetter performance using fewer drives•• enhanced reliability compared to traditional drivesenhanced reliability compared to traditional drives•• adopting adopting tieringtiering strategy can lower TCO and ROIstrategy can lower TCO and ROI•• visible cost savings on energy, space, maintenance a nd visible cost savings on energy, space, maintenance a nd

administrationadministration•• not necessary to use Enterprise SSD for all application datanot necessary to use Enterprise SSD for all application data

–– only critical elements should be kept on Enterprise SSDonly critical elements should be kept on Enterprise SSD

•• RecommendationRecommendation–– if possible, use thin provisioning and automatic if possible, use thin provisioning and automatic tieringtiering

technologies on your storage systemstechnologies on your storage systems