1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T Series L TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 10 (12/2014) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT ITU-T L.1300 Supplement on verification expe
2、riments related to increase of efficiency of air-conditioning and control technologies at a data centre ITU-T L-series Recommendations Supplement 10 L series Supplement 10 (12/2014) i Supplement 10 to ITU-T L-series Recommendations ITU-T L.1300 Supplement on verification experiments related to incre
3、ase of efficiency of air-conditioning and control technologies at a data centre Summary Supplement 10 to the ITU-T L series of Recommendations refers to the best practices defined in Recommendation ITU-T L.1300. More precisely, this Supplement provides an overview of verification experiments related
4、 to the increase of efficiency of air-conditioning and control technologies. The results of such verification experiments are provided and an estimation of their applicability to real data centres is reported. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T L Suppl. 10 2014-
5、12-19 5 11.1002/1000/12438 Keywords Best practice, data centre, energy efficient, information and communication technology and climate change (ICT results of verification experiments; and estimates of applying results to actual data centres. 2 Definitions This Supplement uses the following terms: 2.
6、1 climate change b-IPCC: Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. Climate change may
7、be due to natural internal processes or external forcing, or to persistent anthropogenic changes in the composition of the atmosphere or in land use. Note that the Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: a change of climate which is attributed di
8、rectly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. The UNFCCC thus makes a distinction between climate change attributable to human activities altering the atmosphe
9、ric composition, and climate variability attributable to natural causes. 2.2 greenhouse gas b-ISO 14064-1: Gaseous constituent of the atmosphere, both natural and anthropogenic, that absorbs and emits radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earths s
10、urface, the atmosphere and clouds. 3 Abbreviations and acronyms This Supplement uses the following abbreviations and acronyms: CPU Central Processing Unit GHG Greenhouse Gas PUE Power Usage Effectiveness VM Virtual Machine 4 Background and purpose It is predicted that the power consumption in data c
11、entres in the world will keep on increasing in the future, and reduction of power consumption is required from the viewpoints of influence over global warming issues and operation costs. On the other hand, it appears that various operational systems of businesses will make transition to cloud servic
12、e, and it is forecasted that variation of the workload in data centres by the time of the day becomes large. Against such problems, elimination of wasteful power consumption is studied by allocation of necessary calculation resources and cooling capacity as matched with the variation of the workload
13、. 2 L series Supplement 10 (12/2014) By conducting verification experiments, the power saving effect is verified on a simulated data centre, applied energy-saving technologies that integrated control of ICT devices and air-conditioning equipment against workload variation. Furthermore, the energy-sa
14、ving effect of a case where the application is expanded to two data centres is also verified. This experiment was executed as a verification of the technique for the reduction of the energy consumption of the data centre, contributing to reduction of GHG and control of Climate Change, by Ministry of
15、 Internal Affairs and Communications Japan and FUJITSU Ltd. in FY 2011. 5 Overview of experiments 5.1 Control method The power consumption reducing effect is verified on three control technologies indicated below by these verification experiments. Figures 1 and 2 show an overview of control method.
16、1) ICT load consolidation control Executes workload consolidation control so that server power consumption can be reduced against workload variation. 2) ICT linked air-conditioning control Executes air-conditioning control so that air-conditioner power consumption can be reduced in correspondence to
17、 the heat value from servers. 3) Remote load distribution Executes workload distribution so that the entire power consumption can be reduced in such an environment that two data centres located in a distance to each other have identical calculating functions and are able to execute distributed proce
18、ssing of the workload. Figure 1 Overview of controls L series Supplement 10 (12/2014) 3 Figure 2 Overview of remote load distribution 5.1.1 ICT load consolidation control A server is consuming a certain amount of electric energy in general even if it is in an idle state with zero workload as shown i
19、n Figure 3. Under these circumstances, the total power consumption of the entire server group is reduced by concentrating the workload to partial servers and by turning off the power for servers, the workload to which becomes 0. The workload is allocated to servers so that the CPU usage rate of a se
20、rver becomes 60 to 80%. Figure 3 Example of server power consumption characteristics Figure 4 Flow of ICT load consolidation control 5.1.2 ICT linked air-conditioning control In the conventional air-conditioning control, the air-conditioner supply temperature and airflow are fixed, and the supply te
21、mperature and airflow that are required against maximum heat value and fan airflow are set. On the contrary, this control sets the air-conditioner supply temperature and airflow so the energy what is minimum required for cooling the heat generated by the server. 4 L series Supplement 10 (12/2014) Ou
22、tdoor air cooling systems was used for the experiments, and the cold aisle was separated from the hot aisle. Accordingly, air-conditioner characteristics and conditions such as what are indicated below are provided. The air-conditioner supply temperature is almost linked with the server inlet air te
23、mperature. It is necessary that the air-conditioner supply airflow is set at a level that is higher than the total airflow of server fans. The power consumption is higher in the case where the air-conditioner supply airflow is made higher than the case where the air-conditioner supply temperature is
24、 turned down. The power consumption by the air-conditioning system depends on the air-conditioner power consumption and the server fan power consumption. The server fan power consumption can be minimized by keeping the inlet air temperature at a certain level or less as shown in Figure 5. The air-co
25、nditioner supply temperature is controlled so that the server inlet air temperature is kept at a certain level or less, and the air-conditioner supply airflow is controlled at a level that is higher than the fan airflow at this occasion, in these experiments. Figure 5 Example of server fan character
26、istics Figure 6 Flow of ICT linked air-conditioning control 5.1.3 Remote load distribution Two data centres are of different power consumption levels against the workload (server heat value) by the differences in air-conditioning equipment and open air conditions, as shown in Figure 7. Based on this
27、 relation, the workload is distributed to these two data centres so that the total power consumption of two data centres is minimized as shown in Figure 8. The power for the air conditioner was not turned off in these experiments even while the workload is zero. L series Supplement 10 (12/2014) 5 Fi
28、gure 7 Relation between data centre workload and power consumption Figure 8 Relation between workload allocation and power consumption (Where the overall workload is expressed as 100) 5.2 Experiment items Experiments were conducted on five control methods shown in Table 1 during the verification exp
29、eriments. Experiments 1 to 4 were conducted using one simulated data centre, and experiment 5 was conducted using two simulated data centres. Outdoor air condition was changed at experiment 5. Outdoor air condition was decided by reference to a climate at Sapporo in Japan. Each experiment continues
30、for two days (48 hours) or longer, and the power consumption of ICT devices and air-conditioning equipment was measured. Table 1 List of experiment items No. ICT load consolidation control ICT linked air-conditioning control Remote load distribution Outdoor air condition Data centre 1 Data centre 2
31、1 Middle 2 Middle 3 Middle 4 Middle 5-1 High Natural 5-2 Middle Natural 5-3 Low Natural 6 L series Supplement 10 (12/2014) Table 2 Outdoor air conditions in data centre 1 Temperature (C) Humidity (%) High temperature 22 75 Middle temperature 12 66 Low temperature 7 62 5.3 System for experiments 5.3.
32、1 Simulated data centres Experimental laboratory 1 and experimental laboratory 2 shown in Figure 9 were used as simulated data centres. Table 1 indicates specifications for these experimental laboratories. Furthermore, Figure 10 shows photos indicating external appearances of experimental laboratory
33、 1 and experimental laboratory 2. As ICT devices, actual servers and simulated servers that simulate the server heat value and airflow were used in each experimental laboratory. ICT devices were of the same configuration in two experimental laboratories. The configuration of ICT devices in experimen
34、tal laboratories is shown in Table 3. One simulated server is able to generate heat of about 4 kW, and one simulated server generated heat value and airflow of ten servers in the experiments. Regarding air-conditioning systems, the air-conditioning heat source system diagram for experimental laborat
35、ory 1 and the same for experimental laboratory 2 are shown respectively in Figures 11 and 12. A data centre of good cooling efficiency was simulated using an outdoor air cooling system in experimental laboratory 1. Open air temperature and humidity can be artificially generated. Each of experimental
36、 laboratory 1 and experimental laboratory 2 was partitioned so as not to allow mixing of air flow between the cold aisle and hot aisle. Table 3 Specification for experimental laboratories Room 1 Room 2 Area About 7 m 5 m About 6.4 m 4.8 m Number of racks 8 8 Air cooling General cooling and outdoor a
37、ir cooling General cooling Table 4 Specification for ICT devices Room 1 Room 2 ICT devices 6 servers, 1 storage, 2 network switches 5 servers, 1 storage, 2 network switches Number of simulated servers 16 16 Total heat value 48kW 48kW L series Supplement 10 (12/2014) 7 Figure 9 Outline of experimenta
38、l room Figure 10 Appearance of experimental room 8 L series Supplement 10 (12/2014) Figure 11 System diagram of air conditioning and heat source in experimental room 1 Figure 12 System diagram of air conditioning and heat source in experimental room 2 5.3.2 Simulated operational system As a business
39、 system that operates in the data centres, a typical Web application, an in-house document retrieval system was used. This system allows employees to retrieve documents spread across the company (including product information, reports, meeting minutes, proposals, and estimates) in a batch, using som
40、e keywords. In this experiment, a virtualization system was configured assuming a general data centre, and retrieval servers owned by four companies operate on L series Supplement 10 (12/2014) 9 a VM (virtual machine). The capacity of the storage device in which retrieval databases were stored was 3
41、TB. In this system, the workload was adjusted based on the number of retrieval requests, and as the daily variation pattern of the workload, it was assumed that the workload varied with routine works and was the highest in the daytime. Additionally, retrieval databases were updated through nightly b
42、atch processing. Figure 13 shows the daily workload data of the accumulated requests coming from four companies. This experiment started from the workload data as of 6:00 a.m. and was repeated two times for two days. Figure 13 Daily workload data 5.3.3 Control system Figure 14 shows the configuratio
43、n of the control system. The input parameters for control include the amount of the workload and the measured inlet air temperature and CPU temperature of the racks. The ICT load consolidation control results in controlling on/off of the server through the VM control unit and specifying the heat val
44、ue and airflow to the simulated server. The ICT linked air-conditioning control results in specifying the supply temperature and airflow to the air conditioner. Figure 14 Overview of control system 10 L series Supplement 10 (12/2014) 5.3.4 Measurement system Table 5 shows the main measurement items.
45、 In this experiment, data was collected at intervals of 30 seconds, which was sent to the control system and recorded and stored in a data logger. Table 5 List of measurement items Item Place Target Device Power consumption Experimental laboratory Rack Electricity meter Lighting Electricity meter Ai
46、r-conditioning equipment General air cooling, pump Electricity meter Air blower Electricity meter Chiller, cold water pump Electricity meter Temperature Experimental laboratory Rack (in, out) Temperature sensor Wall surface Temperature sensor Open air Open air Temperature sensor Air-conditioning equ
47、ipment Supply air, inlet air Temperature sensor Heat quantity of cold water Temperature sensor Humidity Experimental laboratory Rack (in, out) Humidity sensor Wall surface Humidity sensor Open air Open air Humidity sensor Air-conditioning equipment Supply air, inlet air Humidity sensor Airflow and w
48、ater volume Air-conditioning equipment Supply air, inlet air Airflow sensor Heat quantity of cold water Water flow sensor 6 Results of experiments 6.1 Experiment (1) Experiment (1) verified the efficiency of the conventional method, without applying both the ICT load consolidation control and the IC
49、T linked air-conditioning control methods. The load was allocated to the servers evenly, and the air-conditioning supply temperature and airflow were fixed. The supply temperature and airflow of the air conditioner were set to 24C and 20000 m3/h, respectively. Figure 15 shows the measured data of the power consumption of the ICT devices and the air-conditioner, as well as the overall power consumption. This shows that the variation of the power consumption of ICT devices was smal
