Cloud Data Center/Storage Power Efficiency Solutions

Junyao Zhang

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Current Storage Energy Efficiency Solutions: Tradeoff Energy/Performance

Multi-speed Disk: DRPM CPU has Dynamic Voltage and Frequency Scaling

(DVFS): can we use this idea on storage systems?

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VM Consolidation: SRCMap

Request Consolidation (Replication-based): EERAID, Diverted Access Redirect requests to some replicas to spin down

the others

Data Consolidation: MAID, PDC Skew data into partial disks/cache disks so

that others can be shut down

In what degree should we tradeoff energy/performance?

Power Proportional A standard metric proposed by Google [1]:

Computer components should consume energy in proportion to the system utilization.

Observation:

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Robust and Flexible Power-Proportional Storage

Strictly satisfy power proportional :

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Solution

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Fine-grained power proportionality for one data-set

More

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Read Performance

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Write Performance

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Handling Recovery Bounded wake-up Rebuild is power-

proportional

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Near power-proportional(cnt.)

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Multi-data set: Fair Scheduling

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Degradation

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Sierra: Practical Power-proportionalilty for Data Center Storage

Power proportional layout with the concern of the following factors: Fault-tolerance, Loading balance, Consistency, Good

performance.

Three challenges: Layout that allows significant power savings Maintain read and write availability at the original

levels Predict the number of servers required at anytime

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C1: Power-aware Layout

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Gear 1 (g=1): need 2 nodes (Gear group 0) to keep 1 the copy of all nodes

Gear 2 (g=2): 4 nodes

C1: Power-aware Layout Extending to three replicas and more: two options

Rack-aligned Rotated

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C2: Distributed virtual log (DVL)

Aim: maintain read/write availability Write: if secondaries not available, entering

“logging mode”(write primary replicas to DVL and replicate DVL r-1 times )

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C3: Gear Scheduler Aim: predict system load and schedules servers to

power down or up accordingly. Observation: predict hourly behavior based on

historical records of this hour.

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Power Savings

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Performance

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Response Time

Conclusion Power proportional is becoming an important

metric for power/energy tradeoff Rabbit proposed a idea-power proportional

layout Sierra considered factors such as: power,

reliability, load balancing, consistency and etc.

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[1] L. A. Barroso and U. H¨olzle. The case for energy-proportional computing. Computer, 40(12):33–37, 2007.[2] E. Thereska, A. Donnelly, and D. Narayanan. Sierra: a powerproportional, distributed storage system. MSR-TR-2009-153, November 2009.[3] H. Amur, J. Cipar, V. Gupta, G. R. Ganger, M. A. Kozuch, and K. Schwan. Robust and flexible power-proportional storage. In SoCC, 2010.

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Thank you

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