Research on Energy Consumption of General Network Storage System

1. Research on Energy Consumption of General Network Storage System Liang Kai,Xiaofang Zhang, Xiao Zhang Northwestern Polytechnical University 2011-7-28

2. Outline • Background • Energy consumption model • Experiments • Conclusion and Future work

3. 300 Power and Cooling Costs Server Mgt and Admin Costs 250 New Server Spending 200 150 100 50 $0B 1997 1999 2001 2004 1996 1998 2002 2003 2000 2005 2007 2009 2010 2006 2008 Challenge Global Annual IT Spending Estimated US$B 1996-2010 Source: IBM Corporate Strategy analysis of IDC data, Sept. 2007

4. Background Huge energy consumption in Network Storage Systems From the perspective of the whole system accurately reflect real-time energy consumption Some energy consumption standard has been released in industry Research on Energy Consumption of General Network Storage System Thesis signigicance Energy conservation, green storage promote low-carbon economy China promote the development of network storage technology Analyse, establish the generalenergy consumption model of networks storage system Reseach purpose Thesis background

5. Structure and research method Conclusions Reseach on EC of NSS Analysis and test EC  Verify model validation Introduction Establish EC model Server EC Switch EC Disk array EC Based on system expansion and workload conditions evaluates EC Basic EC Data transmission and Port used number EC Workload EC

6. EC model A common storage network system is consist of the file system servers, switches and disk arrays Energy Consumption = Base Energy Consumption + Variable Energy Consumption according to workload

7. Detail model Servers, switches and disk arrays are the main functional components of the storage network, and also the major components of the energy consumption. Thus, the full energy consumption of the storage network E should include: server energy consumption Es, switch and disk array energy consumption, Esw, Eda, namely: In the complex structure and changing workload of storage network environment, it refines the energy consumption of each functional part as: basic energy consumption Ebase and workload energy consumption  Eload. Namely: Disk array = Controllers +Disk enclosure + Disks

8. System Extension Considering the added energy consumption for the extended structure in the System-A Eadd. Eadd also includes two parts: the basic and additional energy consumption of the added hardware, Ebase, Esub, namely: The below Table lists the added EC pattern caused by extending hardware in the system.

9. Server-basic EC test 1)Server's Idle Mode energy consumption test: Put the server into the status of single power supply, test the average effective power under the Idle Mode for 10 minutes. The results can be described as follows:

10. Server-Workload EC test Energy consumption test between server and workload: On the server, we use the SPECpower_ssj2008 quantifies energy consumption and generates workloads, test status of the changing server energy consumption. Obtained the test data can be formatted below the figure:

11. Switch EC test 1)Basic EC：The basic energy consumption test of switch: The method of the basic energy consumption test on switch is identical to that of server Idle Mode. The result in our environment is 17.93W 2) EC per activate port: The energy consumption test between switch and the number of used port: Make the switch in the state of no host accessing, one by one join 8 hosts, each of the states hold for 5 minutes. Test on every added a port leads to energy consumption increase. The result is 1.06W 3)EC change according to data transfer: It's difficult to quantify and control the specific data transferred rate of the switch. So, assuming that the data transmission of the switch has only two states: full-bandwidth data transmission and no data transmission, using the Iperf control full-bandwidth data transmission between a pair ports. EC changes very little. Switch takes a small role in the whole system

12. Disk array EC test 1)Basic EC Test: The basic energy consumption test on the hardware of disk array: Successively increase components in the disk array  (disk block number from 5 to 15, the disk enclosure from 0 to 1), use Power Analyzer to detect the  changed information of power, get the energy consumption status by calculated on the various components of the disk array. 2)Workload EC Test:The energy consumption test between disk array and the workload: Read and write IO operation of the disk array is the main workload, usually indicated by the values of ​​IOPS, which is controlled by IOPSCtrl  in this test. In the RAID's organizational model , RAID0 has non-redundant operation and the least impact on disk's energy consumption, so all the disk blocks on disk array is comprised of the RAID0 mode , and the full capacity of which mount  to a directory on the server to test the maximum value of IOPS in disk by Iometer. From no IO operation, every 10% of the maximum IOPS until the maximum workload is increased by IOPSCtrl, each state for 10 minutes. Experiments show workload takes little affect on EC, We think disk keep working even there isn’t any IO operation. But MAID2.0 technology may change this.

13. Verification • Use one server and one switch and one disk array to verify the model. According the model, calculate result is 828.993W; Test result of 830.352W, difference is very little.

14. General usage • If there are X servers , Y disks and  L pairs of the ports in the network storage system, the entire system's total energy consumption:

15. Future work • Cooling system EC takes a import role in data center, we need take temperature into consider in the future. • New medias such as SSD will have different EC features. • Some green technologies need more researches. MAID(massive array of idle disks) slow down the rotation speed of disk to save energy. • Need more experiments in big system to verify the model.

16. Thanks