2012 Eighth International Conference on Semantics, Knowledge and Grids
Enabling Green IT Through Building a Virtual Desktop Infrastructure Don-Anthony DaSilva1, Lu Liu1,2, Nik Bessis1, Yongzhao Zhan2 1
School of Computing and Mathematics, University of Derby, Derby, United Kingdom School of Computer Science and Telecommunication Engineering, Jiangsu University, Jiangsu, China
[email protected]
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consolidating end-user PCs as virtual desktops which run on servers in the data center (DC) while meeting both the needs of users and administrators. Admins can manage thousands of virtual desktops from a single console, and allow end users anytime anywhere access through a variety of devices. This rest of paper is organised as follows: Related Work on desktop virtualization, green IT and thin computing is presented in section II. The experiment system design is described in section III. The experimental results are analysed in section IV. The observations from experiments and testing are discussed in section V. Finally, the conclusion is given in section VI.
Abstract— The recent cuts being made in IT budgets across the globe can be attributed to any number of modern day crises. For instance, organizations are still recovering from the recession almost 5 years later, and IT infrastructures have been having to deal with reduced budgets and still expected to deliver the service that clients are accustomed to. Addressing the challenges presented in the modern day data enter has also been a serious, especially in regard to the rising energy cost the global warming issue. This paper looks at the literature behind virtualization and mainly virtual desktop infrastructure as the solution to these issues. Through this research and the implementation of a small test virtual desktop environment using VMware and Wyse technology, it was able to portray the clear improvements that hypervisor and desktop virtual can bring to IT infrastructures drawing particular attention to power consumption and the green incentives.
II.
A. Desktop Virtualization With Virtual Desktop infrastructure (VDI), companies can host individual desktops inside virtual machines that are provisioned in the DCs. Users access these desktops remotely from a PC or a thin client using a remote display protocol. Since the O/S and applications are managed centrally at the corporate Data Center, organizations gain better control and security over their desktops without degrading the user experience. Installations, upgrades, patches and backups can be done with more confidence and without user intervention. Desktop virtualization is being deployed more in industries such as financial services, education, medical/health care and the government. Places where tasks are more repetitive. This enables IT administration and endusers to be flexible in carrying out their tasks. Outside of these institutions, infrastructures have struggled to realize the benefits of virtual desktops mainly because the end-user experience has not met the expectations beyond the traditional client model in some aspects, namely application performance. Application performance is to some extent a barrier to virtualization. VDI environments differ to virtual server environments in that server virtualization is often aimed at consolidation and private cloud initializations [11]. According to Greene, Gartner says 40% of servers overall have been virtualized, but that the penetration will grow to 75% in 2015 [2]. Virtualization threatens the $3 trillion spent each year on corporate computing hardware [3]. With embracing virtual desktops, what really lies ahead is the innovation of thin client computing and windows 8
Keywords-component; Virtualization; VDI; VMware View; Hosted Virtual Desktosp;Green IT; Power Consumption
I.
INTRODUCTION
Virtualization has been receiving a great deal of attention in recent years, and many believe that it was only developed as of late, when in actuality virtualization has been around for over 40 years. The concept originated with the IBM mainframe System/360, released in 1964, when IBM collaborated with the Massachusetts Institute of` Technology’s Project MAC (Multiple Access Computer) to develop one of the first time-sharing computer systems. This resulted in the VM/370 operating system being developed, which could not only host its own applications, but also other operating systems. The advances in computer technology and development of x86 systems left virtualization trailing behind until VMware introduced virtualization to 86x architecture in 1999 [10]. In the late 1990’s, both Intel and AMD added hardware support to their processors making virtualization utilize x86 processor resources more effectively, and later hardware changes improving efficiency. AMD introduced AMDV and Intel’s VT, which represents virtualization technology on the X86 platforms. In addition, although, there are many different types of virtualization, whichever method is used the goal of consolidation in the IT infrastructure is the same. Now, virtualization is at a stage where it can be deployed at the desktop level, otherwise known as Virtual desktop, essentially delivering desktop-as-a-service [12]. These Virtual desktop infrastructures replace desktop PCs by 978-0-7695-4794-7/12 $26.00 © 2012 IEEE DOI 10.1109/SKG.2012.29
RELATED WORK
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deployment, once it is available, will have a major factor to play in VDI consideration.
have been identified as the primary contributor of carbon emissions and predicted to become the top source of greenhouse gas pollution by 2020 [5]. The use of virtualization in the DC at the hypervisor level on platforms such as ESXi and XenServer greatly reduces the carbon footprint and cuts energy consumption. Figure 1 depicts a visual of the global warming potential desktops PCs and thin clients have; clearly showing how the use of thin clients even with server utilization still reduces the impact significantly.
B. Thin Computing Thin Computing delivers the productivity people need, at a lower cost than traditional methods, all without compromising security or manageability. Thin Computing replaces the PC with a thin client or zero clients, making it easier for IT to manage user desktops by moving their complexity to the cloud, or a DC using desktop virtualization [13]. The term ‘Thin-Client’ was coined in 1993 and the technology behind it is nothing new. Thin clients run on a stripped down custom OS (Linux, Windows, Java, UNIX, etc.) and this embedded OS is what provides the functionality of the device allowing a remote connection to the DC. Thin devices use no more than around 40 watts as opposed to the 300 and greater watts used by PCs. This means less energy consumption and offers infrastructures a green incentive which will be discussed further in this report. Whilst mobile device sales have already begun to close the market gap between PC sales it is only a matter of time before thin devices do the same and eventually surpass them, in particular zero client devices. Especially once the dynamic functionalities that zero client technology brings to a VDI environment are realized.
Figure 1. GWP of Thin clients and Desktop PCs [4]
James and Hopkinson point out that power consumption and CO2 emission are the main contributors to greenhouse gas pollution, in particular CO2 [4]. IT infrastructures facing rising energy bills, limited DC space, and pressure to be green are turning to green technology to ease the pain and should embrace the shift to virtualization to do so. The following section seeks to outline and discuss the specifications of the project and any test which has be carried out.
C. Green IT With IT moving away from the conventional single OS to single server model to a virtualized infrastructure, they leave behind the need for introducing additional physical machines to handle increased workload. They no longer need to concern over DC capacity or physical resource management [8]. Companies are being put under pressure to reduce their emissions and impact on the environment. This is pushing them towards server consolidation with virtualization which has been identified as a promising green technology, by reducing the number of physical components an also overcoming server sprawl with underutilized servers. According to IDC most companies, given their limited IT budget, will be putting their money where it will have the most impact: green IT [1]. Desktop virtualization incorporating the use of thin and zero clients which lack moving parts and built on energy efficient hardware reduced consume a lot less power as opposed to conventional systems. Thin client computing is generally designed to be highly energy efficient hardware as well as reliable. The life span of a typical PC is approximately 3 years due to the advances in components and functionality, as opposed to the 5-7 years thin clients offer [7]. This longer lifespan can be attributed to the fact that these devices mainly rely on the technology within the DC instead of local components and have a lower chance of experiencing failures in hardware. Although, since DCs
III.
EXPERIMENT
Figure 2. Overview of VDI Environment
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IV.
After extensive research into the current virtual desktop trends and the literature review has been completed. An experiment has been be carried out to investigate the potential impact of VDI for HE institutions, while clearly identifying the issues that can be solved in applying a VMware VDI solution as shown in Figure 2. A vSphere server, VMware view manager server and ESX server has been required for the virtual environment. VMware VSphere has been used to manage the virtual environment, while the view manager acts as a connection broker managing user access to the centralized virtual desktops, and the ESX server hosts the virtual machines.
Power consumption of the thin client and desktop PCs were recorded using a standard power meter over the period of 2 minutes. Additionally, it was noted that external factors such as room temperature and workloads may affect results. As a result, tests were run at an average room temperature of between 20-250C and taken while the devices were in various states. Additionally, data analyzed has been collected while devices are with and without monitor display (raw consumption), running various workloads and in an idle state. These various conditions also provide some insight as to the effects on consumption in a regular real world environment. The results demonstrate the power usage in watts of desktop PCs rolled out in a live environment, although workloads were simulated with the use of Prime95. Prime 95 has been used to enhance CPU and RAM utilization; this utilization is shown below in Table 3.
A. Hardware Requirement The preliminary hardware requirements for the project have been listed in the table 1 below along with the software requirements listed separately. Table 1. Hardware requirements
Hardware Server Wyse Thin Client
Quantity 3
Specification Each machine was identical
1
C10 LE with Wyse Thin OS
Cisco 2960 Switch
1
Power Monitor
1
Table 3. Workload and Resource usage correlation
Workload
Medium workload Heavy workload
VMware ESXi VMware vSphere Client MS SQL Server Express VMware vCenter Server
CPU 5-20% utilization Memory 20% utilization CPU 25-55% utilization Memory 40% utilization CPU 60-90% utilization Memory 75% utilization
A. Power Consumption with Display The results of the power consumption test carried out on desktop PCs also include the watts used by the 17” LCD monitors. The PCs and monitors were plugged connected to a power supply by a ‘Dual Y IEC Splitter’ otherwise known as a Y splitter. This was done to obtain results as accurate as possible, as desktops would never be used without monitor display, which allows for a more precise calculation of cost involved.
Table 2. Hardware requirements
VMware View Agent VMware View client
Utilization
Idle
This allowed network communication between devices. This device was used to measure the power consumption
B. Software Requirements/components The software requirements and components are show in Table 2.
VMware View connection
FINDINGS AND ANALYSIS
acts as a connection broker providing authentication and access to remote desktops installed on virtual desktops installed on client devices for connecting to desktops ESXi 5.0 is the latest VMware hypervisor release which is installed, and run with or in place of the traditional operating system managing ESX/ESXi host and vCenter server Vcenter server requires an SQL database to function the management tool for ESXi offering complete control and visibility over clusters, hosts, virtual machines, storage, networking and other critical elements of your virtual infrastructure
Figure 3. Desktop PC with Monitor
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Although, in a real world environment it is highly unlikely like a desktop or thin client will be used without some sort of display. These results are aimed to reflect the raw consumption of the devices themselves. It should be noted that a separate test was carried out on a 17” LCD monitor just to determine the exact influence on the results and they revealed the power consumption of the LCD monitor remained at a stabled rate of 23 watts per second.
Figure 3 shows the consumption when the PC is accessing the local desktop and nothing is being done or for instance, the user is currently doing some light word processing or checking e-mails. The power consumption with a total average of 84 watts fluctuated from as low as 82 watts and reaching a high of 101 watts over the period of 2 minutes. Then when a medium level workload was applied the consumption experienced an overall average of 120.5 watts which is significantly higher when compared to the light/idle workload, whereas the fluctuation in the recordings was not as noticeable ranging from 118 to 122 watts. The same could also be seen in the heavy processing workload ranging from 125-129 watts. The figure clearly depicts that the difference in watts consumed under the medium and heavy workloads was only slight with the difference in their total average consumption being approximately 6 watts. Where these stats stand out in this experiment is when they are put up against the power consumption of the thin client device running on a Wyse thin OS.
C. Power Consumption with thin client connected to desktop From Table 4 it was evident that the Wyse thin client running Wyse thin OS still consumed a significantly smaller amount of energy even with an active RDP session to a VM hosted within ESXi server. In a production environment with the device fully operational and connected to a display, as well as usb mouse and keyboard power consumption was still considerably less than that of the idle desktop workstation. Table 4. Thin Client connected to Hosted Virtual Desktop
B. The Power Consumption of Thin Client and Desktop PC (Without Display) The Figures 4 and 5 show the power consumption recorded for an idle thin client and desktop PC with a more significant difference in consumption than what was originally expected.
Thin Client (Wyse C10LE) Time 1st 2nd (Sec) Test Test 5 7 8 10 7 9 15 7 9 20 6 8 25 7 9 30 6 7 35 6 8 40 7 8 45 7 9 50 6 8 55 7 9 60 6 9 65 6 8 70 6 7 75 7 6 80 7 7 85 7 7 90 7 7 95 7 8 100 6 9 105 7 7 110 6 8 115 7 8 120 7 9
Figure 4. Thin Client vs PC Power Consumption over 2 minutes
Figure 5. Totlal Average Power Consumption: Thin Client vs PC
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Average 7.5 8 8 7 8 6.5 7 7.5 8 7 8 7.5 7 6.5 6.5 7 7 7 7.5 7.5 7 7 7.5 8
With Monitor 30.5 31 31 30 31 29.5 30 30.5 31 30 31 30.5 30 29.5 29.5 30 30 30 30.5 30.5 30 30 30.5 31
E. Power Consumption of ESXi hosts Figure 9 below illustrates the overwhelming difference in energy consumption while physical servers are idle and under heavy workloads as opposed to ESXi server utilizing virtualization at the hypervisor. It can be seen that while the ESXi host is running all 4 VMs it consumes the same amount of power as the physical host while it is under a heavy workload.
The average power consumption only fluctuated slightly by 1-2 watts over time with a total average of 7.3 watts (figure 6). The significantly lower consumption can be directly attributed to the CPU and other light components which comprise the thin client.
Figure 6. Average Power Consumption of active Thin client
D. Power consumption of Physical Host against ESXi Figure 9. Power consumption of Physical and ESXi Host between workloads
Figure 7 shows a substantial response to the various workloads of handling VMs which were carrying out the roles of AD and DNS service. The physical server was left idle with services running and monitored. When comparing it to the results found in Figure 8 showing the power consumption of the ESXi server hosting even more VMs the power consumption was still considerably less. V.
DISCUSSION
This section of the applied research project discusses the observations which were made during the testing and analyzing of data collected. From the results of the test it is clear that CPU and RAM have a direct impact on the power consumption of desktop PCs. It was observed that the under the various workloads the total consumption can vary anywhere between 18-40 watts. From Table 5 it is noticeable that there is not much difference between the consumption in medium and high workload provided by simulated by ‘Prime95’.
Figure 7. Physical Server Power Consumption
Table 5. Average Desktop PC power consumption
PC Consumption (Average) 84.0
Idle
120.5
Medium
126.8
Heavy
Figure 8. ESXi Host Power Consumption
Most of the energy consumption can be attributed to the CPU and the fan of the desktop machines as during the different workloads not much memory was used with the
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users and IT would expect [9]. From the results of the experiment by incorporating the use of lightweight machines with no moving parts uses significantly less energy than ‘traditional’ desktop PCs. In measuring the power consumption and the RAM and CPU utilization of physical and virtualized host it was clear that with the shift to VDI would also offer a much more effective use of resources at the server level, especially through server consolidation. To conclude, although the initial on set in adopting any of the VDI solutions mentioned can be quite costly, the long term cost savings from improved TCO and from using green technology would benefit any modern day infrastructure.
exception of the heavy workload. This then leads into the consumption that was observed on the physical servers and ESXi host; the average of the results collected can be seen in Tables 6 and 7 below. Table 6. Physical Server Power Consumption
Physical Server Consumption (Average) 100.9
Idle
131.8
Medium
144.5
High
Table 7. ESXi Server Power Consumption
ESXi Host Consumption (Average) 32.8
Idle
ACKNOWLEDGMENT
102.6
High
The work reported in this paper has been supported by the RLTF HECloud Programme (Ref: RLTFD005), Visiting Scholar foundation of Key Laboratory of Dependable Service Computing in Cyber Physical Society (CPS-DSC 2012FWJJ01), Major Program of the National Natural Science Foundation of China, under contact No. 90818028 and China 973 Fundamental R&D Program (No. 2011CB302600).
This shows how more resource efficient the virtualization technology behind hosted virtual desktops can benefit the infrastructure. This shows how underutilized the physical components of a physical conventional server environment. On the ESXi within the sample environment it was noticed that while running 3 virtual server machines and virtual workstation that the CPU was barely utilized, while most of the processing was handled by the RAM. With virtualization the utilization rates can reach anywhere between 80-90%, whereas on a physical server only about 50% of its memory is utilized for intense workloads, stressing the CPU which causes the high energy consumption. It was noted through the entirely of the testing stage that the CPU was responsible for most of the consumption on all physical devices operating at almost 90% whereas only 30-50% of its RAM was being used. The opposite was noticed on the ESXi host where the 4VMs utilized almost 80-90% of the memory and only around 10% of the dual core CPU processor. VI.
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[3]
[4]
CONCLUSION
This paper has identified the current trend in desktop virtualization, as well as effectively covers all relevant literature in order to achieve the aims and objective which were set. In a typical environment x86 desktops and servers are idle most of the time leading to massive power consumption and to rectify this virtualization has appeared to be the top of organizations lists. Although, in recent time with reduced technology budgets and recession, increasing server and desktop virtualization can be an effective way for infrastructures to save on hardware as well as deploy new servers and desktops more quickly and cost-effectively, with less strain IT staff. Furthermore, virtualization can help extend the life of their legacy environments. The main goal in adopting VDI and the thin client model is centralized management and resources utilization, without having to compromise on the quality of service that end
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