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Reliability Modeling and Analysis of Energy-Efficient Storage Systems
Shu Yin
Advisor: Dr. Xiao QinCommittee Members: Dr. Sanjeev Baskiyar
Dr. Alvin LimUniversity Reader: Dr. Shiwen Mao
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Presentation Outline
MotivationMINT ModelMREED ModelModels ValidationReliability ImprovementConclusion and Future Work
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Motivation
Data Intensive Applications
Stream Multimedia Bioinformatic
3D Graphic
BioinformaticBioinformatic
Weather Forecast
Bioinformatic
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Data Intensive Computing Application
Cluster System
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Problem: Energy Dissipation
EPA Report to Congress on Server and Data Center Energy Efficiency, 2007
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Problem:Energy Dissipation(cont.)
Using 2010 Historical Trends Scenario
Data Centers consume 110 Billion kWh per Year;
Assume Average Commercial End User Is Charged ¢9.46 per kWh
Disk System Can Account for 27% of the Computing Energy Cost of Data Centers.
Disk Syste
m27%
Other73%
Disk System May Have An Electrical Cost of
2.8 Billion Dollars!
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Existing Energy Conservation Techniques
Software-Directed Power ManagementDynamic Power ManagementRedundancy TechniqueMulti- speed Setting
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How Reliable Are They?
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Contradictory of Energy Efficiency and Reliability
Example: Disk Spin Up and Down
Energy Efficiency
Reliability
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Presentation Outline
Motivation
MINT ModelMREED ModelModels ValidationReliability ImprovementConclusion and Future Work
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MINT(MATHEMATICAL RELIABILITY MODELS FOR ENERGY-EFFICIENT PARALLEL DISK SYSTEMS)
Energy Conservation Techniques
Single Disk Reliability Model
System-Level Reliability Model
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Frequency Utilization
Disk Age Temperature
Reliability of Single Disk
Single Disk Reliability Model
MINT(Single Disk)
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MINT(Single Disk)
R=α*BaseValue[1]*TemperatureFactor+β*FrequencyAdder[2]
α and β are two coefficients to R
Assumption: α = β = 1 in our research
[1] E. Pinheiro, W.-D. Weber, and L.A. Barroso. Failure trends in a large disk drive population. Proc. USENIX Conf. File and Storage Tech., February2007.
[2] IDEMA Standards. Specification of hard disk drive reliability.
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MINT(Single Disk)
R=α*BaseValue*TemperatureFactor+β*FrequencyAdder
Utilization Impact on AFR
Temperature Impact on Temperature Factor
Transition Frequency Impact on Frequency Adder
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MINT(Single Disk)
R=α*BaseValue*TemperatureFactor+β*FrequencyAdder
Single Disk Reliability
Frequency=250/Month, T=40°C
Frequency=350/Month, T=35°C
Frequency=250/Month, T=35°C
Base Value from Google Report[3]
[3] E. Pinheiro, W.-D. Weber, and L.A. Barroso. Failure trends in a large disk drive population. Proc. USENIX Conf. File and Storage Tech., February 2007.
Frequency=350/Month, T=40°C
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MINT(Energy Conservation Techniques- PDC)
- hot data
- cold dataPopular Date Concentration (PDC)[3]
System Structure
[3] E. Pinheiro and R. Bianchini. Energy conservation techniques for disk array-based servers. Int’l Conf. on Supercomputing, pages 68–78, June 2004.
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MINT(Energy Conservation Techniques- PDC)
More Popular Disk Less Popular Disk
Access Rate<MIN(Access Rate)
Access Rate<MIN(Access Rate)
Access Rate>MAX(Access Rate)
Access Rate>MAX(Access Rate)
- hot data
- cold data
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MINT(Energy Conservation Techniques- PDC)
- hot data
- cold data
(Optimal Result for Certain Time Phases)
Popular Date Concentration (PDC)[3]
System Structure
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MINT(Energy Conservation Techniques- MAID)
- hot data
- cold dataMassive Array of Idle Disks (MAID)[4]
System Structure
[4] Dennis Colarelli and Dirk Grunwald. Massive arrays of idle disks for storage archives. Supercomputing ’02: Proceedings of the 2002 ACM/IEEE conference on Supercomputing, pages 1–11, Los Alamitos, CA, USA, 2002. IEEE Computer Society Press.
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- hot data
- cold dataMassive Array of Idle Disks (MAID)[4]
System Structure
[4] Dennis Colarelli and Dirk Grunwald. Massive arrays of idle disks for storage archives. Supercomputing ’02: Proceedings of the 2002 ACM/IEEE conference on Supercomputing, pages 1–11, Los Alamitos, CA, USA, 2002. IEEE Computer Society Press.
Access Rate>MAX(Access Rate)
Cache Disk Data Disk
MINT(Energy Conservation Techniques- MAID)
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MINT(System-Level)
Energy Conservation Techniques
Single Disk Reliability Model
System-Level Reliability Model
Reliability of Disk 1
Reliability of Disk n
Frequency Utilization
TemperatureAccess Pattern
Frequency Utilization
Disk Age
Reliability of A Parallel Disk System
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Preliminary Results(experimental setting)
Energy-efficiency Scheme
Number of DisksFile Access Rate(No. per month)
File Size(KB)
PDC20 data
(20 in total)0~106 300
MAID-115 data + 5 cache
(20 in total) 0~106 300
MAID-220 data + 5 cache
(25 in total) 0~106 300
Read-only Disks
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Preliminary ResultComparison Between PDC and MAID
AFR Comparison of PDC and MAIDAccess Rate(*104) Impacts on AFR (T=35°C)
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Preliminary ResultComparison Between PDC and MAID
AFR Comparison of PDC and MAIDAccess Rate(*104) Impacts on AFR (T=35°C)
- MAID- PDC
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MAID under High Access Rate
MAID-1
MAID-2
AFR Comparison of PDC and MAIDAccess Rate(*104) Impacts on AFR (T=35°C)
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MAID under High Access Rate
AFR Comparison of PDC and MAIDAccess Rate(*104) Impacts on AFR (T=35°C)
MAID-1
MAID-2
MAID-1
MAID-2
MAID-1
MAID-2
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MINT(conclusion)
Mathematical Model for Disk Systems MINT Study on PDC and MAIDBut ...
What about RAID?Data Stripping Mechanism
Energy Consumption IssuesReliability Issues
Complexity
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Presentation Outline
MotivationMINT Model
MREED ModelModels ValidationReliability ImprovementConclusion and Future Work
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MREED Model(MATHEMATICAL RELIABILITY MODELS FOR ENERGY-EFFICIENT RAID SYSTEMS)
Access Pattern Temperature
Energy Conservation Techniques
Frequency
Utilization
Annual Failure Rate
Weibull Analysis
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Weibull Analysis
A Leading Method for Fitting Life Date Advantages:
AccurateSmall SamplesWidely Used
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MREED Model(Energy Conservation Techniques- PARAID)
SoftState
RAID
Gears
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Power-Aware RAID (PA-RAID)[5]
System Structure
[5] Charles Weddle, Mathew Oldhan, Jin Qian, An-I Andy Wang.PARAID: A Gear-Shifting Power-Aware RAID. USENIX FAST 2007.
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Reliability Evaluation(Experiment Setup)
Disk Type Seagate ST3146855FC
Capacity 146 GB
Cache Size Sata 16MB
Buffer to Host Transfer Rate 4Gb/s (Max)
Total Number of Disks 5
File Size 100 MB
Number of Files 1000
Synthetic Trace Poisson Distribution
Time Period 24 Hours
Interval Time (Time Phase) 1 Hour
Power on Hour Per Year 8760 Hours
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Reliability Evaluation(Disk Utilization Comparison)
Disk Utilization Comparison Between PARAID-0 and RAID-0 at A Low Access Rate (20/hr)
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Reliability Evaluation(Disk Utilization Comparison)
Disk Utilization Comparison Between PARAID-0 and RAID-0 at A High Access Rate (80/hr)
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Reliability Evaluation(AFR Comparison)
AFR Comparison Between PARAID-0 and RAID-0 at A Low Access Rate (20/hr)
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Reliability Evaluation(AFR Comparison)
AF
R
AFR Comparison Between PARAID-0 and RAID-0 at A High Access Rate (80/hr)
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Presentation Outline
MotivationMINT ModelMREED Model
Models ValidationReliability ImprovementConclusion and Future Work
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Model Validation
TechniquesRun the Systems for A Couple of Decades
The Event Validity Validation Techniques[6]
[6] R.G. Sargent, “Verification and Validation of Simulation Models”, in Proceedings of the 37 th conference on Winter Simulation, ser. WSC’05 Winter Simulation Conference, 2005.
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Model Validation
ChallengesUnable to Monitor PARAID Running for Years
Sample Size is Small from A Validation Perspective (e.g. 100 Disks for Five Years)
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Model Validation(DiskSim[7] Simulation)
[7] S.W.S John, S. Bucy, Jiri Schindler and G.R. Ganger, “The DiskSim Simulation Environment Version 4.0 Reference Manual”, 2008
File To Block Level Converter
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Model Validation(DiskSim Simulation)
Diagram of the Storage System Corresponding to the DiskSim RAID-0
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Model Validation(Result)
Utilization Comparison Between MREED and DiskSim Simulator
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Model Validation(Result)
Gear Shifting Comparison Between MREED and DiskSim Simulator
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Presentation Outline
MotivationMINT ModelMREED ModelModels Validation
Reliability ImprovementConclusion and Future Work
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Recall PDC
- hot data
- cold data
(Optimal Result for Certain Time Phases)
Popular Date Concentration (PDC)System Structure
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Problem of PDC
The Most Popular Disk:High AFRNo Replica
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Reliability Improvement of PDC
Method of Improving ReliabilityMirroring
Extra Disks for Replication -> More Energy Consumption
Disk SwappingSwap Existing Disks
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Disk Swapping SchemePDC
Swap the Most Popular Disk with the Least Popular Disk
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Swap the Highest AFR Disk with the Lowest AFR Disk
Disk Swapping SchemePDC
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Swap the Cache Disks with the Data Disks
Disk Swapping SchemeMAID
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Preliminary Results(experimental setting)
Energy-efficiency Scheme
Number of DisksFile Access Rate(No. per month)
File Size(KB)
PDC20 data
(20 in total)0~106 300
MAID-115 data + 5 cache
(20 in total) 0~106 300
MAID-220 data + 5 cache
(25 in total) 0~106 300
Read-only Disks
Mean Time to Data Lose (MTTDL)
Swapping Thresholds (2*105, 5*105, 8*105 No./Month)
Single Swapping
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AFR Comparison of PDCAccess Rate(*104) Impacts on AFR
(T=35°C)Threshold = 2*105 No./Month
Comparison of Disk SwapPDC
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Comparison of Disk SwapPDC
AFR:Swap2 < Swap1 < No Swap
AFR Comparison of PDCAccess Rate(*104) Impacts on AFR
(T=35°C)Threshold = 2*105 No./Month
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Comparison Between Different Threshold
PDC
AFR Comparison of PDCAccess Rate(*104) Impacts on AFR
(T=35°C)Threshold = 2*105 No./Month
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Comparison Between Different Threshold
PDC
AFR Comparison of PDCAccess Rate(*104) Impacts on AFR
(T=35°C)Threshold = 5*105 No./Month
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Comparison Between Different Threshold
PDC
AFR Comparison of PDCAccess Rate(*104) Impacts on AFR
(T=35°C)Threshold = 8*105 No./Month
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AFR Comparison of PDCAccess Rate(*104) Impacts on AFR (T=35°C)
Threshold = 2*105 No./Month, 5*105 No./Month, 8*105 No./Month
Comparison Between Different Threshold
PDC
AFRHigher Threshold -> Lower AFR
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Limitations
Read Only Disk Scenario
Data Migration within Certain Time Phases
Simple File Access Patterns
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Future Work
Extend the Models to investigate mixed read/write workloads;
Research the trade-offs between reliability and energy- efficiency;
Extend schemes to a real-world based environment;
Develop a multi-swapping mechanism
balancing the utilization & lowering the failure rate;
Evaluate more control groups.
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Conclusion
Generic Models coupled with power management optimization policies;
Two reliability models for the three well-known energy-saving schemes -- PDC, MAID and PARAID;
Disk swapping strategies to improve disk reliability for PDC.
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Thanks
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Questions?