The document summarizes research on improving the energy efficiency of disk prefetching through modeling, simulation, and implementation. It discusses modeling disk energy consumption and developing principles to increase idle periods and reduce state transitions. A modified DiskSim simulator and Energy Efficient Virtual File System (EEVFS) prototype were created. EEVFS uses parallel striping groups to further improve energy efficiency and performance. Future work includes improving EEVFS for production and studying its scaling capabilities.
Energy Efficient Prefetching – from Models to Implementation
1. Energy Efficient Prefetching – from models to Implementation 05/25/10 Adam Manzanares and Xiao Qin Department of Computer Science and Software Engineering Auburn University http://www.eng.auburn.edu/~xqin [email_address]
6. Motivation EPA Report to Congress on Server and Data Center Energy Efficiency, 2007 05/25/10
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8. Buffer Disk Architecture 05/25/10 RAM Buffer m buffer disks n data disks Buffer Disk Controller Data Partitioning Security Model Load Balancing Power Management Prefetching Disk Requests Energy-Related Reliability Model
9. IBM Ultrastar 36Z15 05/25/10 Transfer Rate 55 MB/s Spin Down Time: T D 1.5 s Active Power: P A 13.5 W Spin Up Time: T U 10.9 s Idle Power: P I 10.2 W Spin Down Energy: E D 13 J Standby Power: P A 2.5 W Spin Up Energy: E U 135 J Break-Even Time: T BE 15.2 S
33. Parallel Striping Groups Group 1 Storage Node 1 Storage Node 2 Group 2 Storage Node 3 Storage Node 4 File 1 File 2 File 3 File 4 05/25/10 Disk 1 Disk 2 Buffer Disk Disk 3 Disk 4 Buffer Disk Disk 5 Disk 6 Buffer Disk Disk 7 Disk 8 Buffer Disk
34. Striping Within a Group Group 1 Storage Node 1 Storage Node 2 1 3 5 7 9 4 6 8 4 6 8 1 3 5 7 9 10 10 1 2 1 2 File 1 File 2 2 2 05/25/10 Disk 1 Disk 2 Buffer Disk Disk 3 Disk 4 Buffer Disk
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36. Testbed 05/25/10 Parameter Storage Server Storage Node CPU Celeron 2.2 GHz Celeron 2.2 GHz Memory (MB) 2000 2000 Network Interconnect 1000 1000 Disk Type SATA SATA Disk Capacity 160 GB 480 GB Disk Bandwidth 126 MB/s 126 MB/s