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.

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]

2. Adam Manzanares Ph.D. May 2010.

3. About me Ph.D.’04, U. of Nebraska-Lincoln 04-07, New Mexico Tech 07-10, Auburn University

4. About My Research Group

6. Motivation EPA Report to Congress on Server and Data Center Energy Efficiency, 2007 05/25/10

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

10. Prefetching Disk 1 Disk 2 Disk 3 Buffer Disk 05/25/10

14. Paramaters Tested 05/25/10 Parameter Values Data Size 1, 5, 10, 25 MB # of Data Disks 4, 8, 12 Inter-arrival Delay 0, 0.1, 0.5, 1 S Hit Rate 85, 90, 95, 100%

15. Energy Savings Hit Rate 85% 05/25/10

16. State Transitions 05/25/10

21. DiskSim with File System Simulator 05/25/10

22. Modified DiskSim Results 05/25/10

25. Energy Efficient Virtual File System 05/25/10

26. EEVFS Process Flow 05/25/10

27. EEVFS Testbed 05/25/10 Parameter Storage Server Storage Node Type 1 Storage Node Type 2 CPU P4 2.0 GHz P4 3.2 GHz P4 2.4 GHz Memory (MB) 2000 1000 512 Network Interconnect 1000 1000 100 Disk Type SATA ATA/133 ATA/133 Disk Capacity 120 GB 80 GB 80 GB Disk Bandwidth 100 MB/s 58 MB/s 34 MB/s

28. Energy Savings 05/25/10

29. State Transitions 05/25/10

30. Response Times 05/25/10

31. Berkeley Web Trace 05/25/10

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

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

37. Measured Results 05/25/10

38. Measured Results 05/25/10

39. Berkeley Web Trace 05/25/10

44. http://www.auburn.edu/~xzq0001

45. Download the presentation slides

46. Download the presentation slides

47. Download the presentation slides

48. Questions