Recent Researches in Circuits, Systems, Communications and Computers

Transcription

1 Comparis of Software Virtualizati Hypervisors JOSEF HORALEK, MARTIN HATAS, VLADIMIR SOBESLAV Department of informati technologies, Faculty of informatics, University of Hradec Králové, Rokitanského 62, Hradec Kralove Czech Republic Abstract: The aim of this paper is to present the testing results of some selected freely available tools for software virtualizati of desktop applicatis and operating systems. The article introduces at first the basic terms and principles of virtualizati and the potential of its use. Csequently we present the selected testing tools and testing method. The measured values are represented by means of graph and its interpretati. On the basis of the measured data, e of the tested tools with the best proved properties of the measured values is recommended. Key-Words: Virtualizati, Windows VirtualPC, Oracle Vistual Box,, memory, test, usability 1 Introducti Virtualizati as a ccept was developed for the first time by IBM in 1960s. During 1980s and 1990s, desktop computers and x86 servers became much more available and, therefore, virtualizati had not underge any significant progress at that period. The client-server applicatis and emergence of operating systems Windows and Linux made both the server technologies and home PCs markedly cheaper. However, new challenges have appeared, such as time-csuming maintenance of the existing computers, high operating cost or high failure rate, which led to the development of x86 virtualizati. Virtualizati has increased the effectiveness dramatically and reduced the overall IT expenses. At present, virtualizati is understood to be a relatively new ccept by means of which many practical problems related to the informati technologies use can be solved [1]. In general, we can say virtualizati is a means allowing creati of the so-called virtual objects. Virtualizati can be performed various levels, from the whole computer to the individual compents creati: We can have a virtual disc, a virtual memory, or a virtual processor. By means of a virtualizati tool, a different operating system can be started in an ing operating system. Virtualizati changes nearly all aspects of the operating system and storages administrati. Using the virtualizati technology, we can create training, testing, or even developmental envirments; there are more possibilities to save physical means and expenses. And we must not forget another important advantage of the virtualizati technology resistance to failures and high availability. Virtualizati allows more operating systems run in e physical machine, e.g. Windows, Linux etc. The number of virtual machines that can run simultaneously in e machine depends hardware specificati. At present, virtual machines are implemented in most data centres as normal servers but with much less maintenance and administrati cost. This technology potential is huge and plays a great role in the computer science future [2]. The aim of this article is to present the basic principles of virtualizati and to recommend a tool for software virtualizati the basis of tests performed with some selected freely available virtualizati tools. The given tool will be then used at the Faculty of Informatics and Management, University of Hradec Králové (FIM UHK) for specific operating system tasks testing. 1.1 Virtualizati benefits Csolidati of servers definitely is the greatest benefit of virtualizati. Virtualizati has become a saving means of about 60% of companies. Their IT departments have been transforming the physical servers to the virtual es. Such transformati has several advantages. Ctinuity of operati and high availability The virtual server is separated from a particular physical hardware and can easily be backed up and restored in another hardware or another locality. Advanced virtualizati technologies thus allow the transfer of a virtual server to another physical server without discnecti of working users, even in applicatis not supporting the high availability soluti at all. ISBN:

2 Scalability The separati of the physical hardware from the individual virtual servers and statis allows an easy increase of the applicatis performance by a simple additi of a new hardware in the existing infrastructure. If, for example, the number of demands made a server is increased, the memory or performance can simply be increased in the administrati csole. The same it is with the additi of any other hardware allowed by the given virtualizati technology. Attendance simplificati and cost of operati reducti Thanks to the reducti of the number of physical servers, automated installati of new servers from templates, their easy transferability to another hardware, and thanks to the centralized administrati tools, the attendance activities during the servers and applicatis installati and operati have been simplified significantly. More effective administrati The symbiosis of a company IT envirment and its commercial needs should be the primary aim of the csolidati. The aim of the IT csolidati is mainly to shorten the period of the return investment in the IT infrastructure and to reduce the expenses related to IT administrati. The administrati of an increasing number of servers, working statis and other devices of the company IT infrastructure can be expensive and demanding from the capacity point of view. Working statis csolidati eliminates the automous administrati disadvantages to a great extent. IT departments can administer and maintain the software such statis much more effectively, including the central applicati of safety patches and correcti packets. A unique, csolidated and csistent envirment in a company can increase the employees labour productivity and reduce the expenses. A unique setting and compliance with the cfigurati policy guarantees much less vulnerability of the centrally administered statis towards the safety threats [1],[2]. view of the tested tools, the full virtualizati principles were used. Under the given cditis, it is the most comm type of virtualizati when all parts of the computer are virtualized. The operating system running in this envirment does not recognize that it has no access to the physical compents of the given machine. The physical layer is divided from the programme layer. All programmes are thus running a virtual hardware. The advantage of such virtualizati is that the virtual compents parameters can be defined (capacity of the disc, memory, etc.) and the programmes are independent the given technical equipment. No hardware change influences the virtual envirment as shown in Figure1. Another advantage is that the physical hardware need not be cnected to the virtual envirment. This means that in full virtualizati, the programmes or operating system can be started in other processor platforms as well, which results in full transferability. In additi to the above mentied advantages, this type of virtualizati has also some disadvantages. Paradoxically, it is just the divisi of the physical and programme level which is the greatest disadvantage because in such case, full performance of the virtual machine cannot be reached although the virtual hardware is an image of the physical e. The reas is that various activities like operatis with the memory, processor instructi, or access to the disc are emulated and not performed directly by the physical hardware. 1.2 Full virtualizati The terminology and classificati of the individual virtualizati types is not uniform. For the purposes of this article, the classificati published in [2] was used. Virtualizati can be classified according to the principle used to a full virtualizati, simulati and emulati, paravirtualizati, virtualizati of storages, virtualizati of networks, and virtualizati of applicatis. From the point of Fig.1 Principles of full virtualizati Full virtualizati allows the use of two architectures, the ed architecture or the hypervisor e. The ed architecture uses the already running operating system in which virtualizati-allowing software has been installed, for example Windows VirtualPC or VirtualBox. The ISBN:

3 other variant is to install the hypervisor directly in the hardware. It then becomes the virtualizati layer running under the virtual machines, for example the ESX server. The operating system ed architecture is called the software virtualizati while the hypervisor architecture is called the hardware virtualizati. 2 Virtualizati tools selecti Virtualizati tools selecti was affected by the certain important factors. The first important is the accessibility of the virtualizati tool. Selected technology is utilized within the educati of computer networks and operating systems. For the purposes of the specified area of interest, we had to select such tools that are easy available and their machine equipment requirements are feasible. Another important selecti parameter was the installati possibilities the Windows XP and Windows 7 platforms, both in the 32bit versi. Typically, the MS Windows XP or 7 is installed it. Such system is administered by a separate entity who is interested in a stable and no-interventi operati. In general, such envirment is not suitable for experimental purposes and virtualizati provides a compromise soluti between the time, safety and lifelikeness of experiments. A set available commly in the informatics laboratories and classrooms has been chosen for the selecti of usable technologies. The limitati given by the use of a comm work stati limited, to some extent, the selecti of offered technologies to those with lesser equipment demands and, therefore, we had to exclude the technologies requiring the inaccessible server technologies. For these reass, three freely available representatives of the software virtualizati were chosen for the testing, namely Oracle VirtualBox [3], Microsoft VirtualPC 2007 [5] a Player [4]. All of the selected technologies were used in default cditi without any interventi in the cfigurati. As referential equipment we used the standard student PCs for to ensure the future utilizati in laboratory envirment. Basic hardware cfigurati parameters: Intel Core 2 Due E4300, 4 GB RAM DDR2 800 MHz, Seagate 500 GB 7200 rot/min and ASUS P5KPL motherboard. 2.1 Tested values selecti To allow an objective comparis, we had to choose such approaches that would represent sufficiently the burden during the use in practice and, at the same time, would have sufficient informative value as to the performance and directi of the individual technologies. We chose the values representing the computing performance of the processor, speed of reading and recording the virtualized hard disc, and the network interface from the point of view of its attendance and throughput. All tests were performed with maximum csiderati of cstant cditis of the running test. Therefore, the same was always used and the ed system was restarted after each measurement. The tested procedure attendance was always provided by a debugged script. If it was possible, the given task was tested in the system as well. The system results were used as reference values. The processor (hereinafter ) was tested in a way allowing the test performance in all tested technologies and comparis and objective assessment of results. For this reas, we chose the Π number computing to a cstant number of decimal digits and encrypting of a testing set of random symbols by the OpenSSL library. The speed of the access to the disc, i.e. to its virtual image, was tested in form of the durati of a 1 GB file copying from e locati to another within the same disc image. Thus both the recording and reading were tested ccurrently. In the network interface, we tested the measurement of the ed system respse from the external source of requests (echo request, echo reply) Tests compositi and technical parameters encrypti test Copying of a randomly generated 1 GB file was tested. The AES (Advanced Encrypti ) symmetric cipher with the 256 bit block was selected for the encrypti. The sequence of commands in the utility script was as follows: (1) system boot up and user login; (2) 90-secd waiting till the system procedures stabilizati; (3) start of the file copying from the root directory to another place as the Timeit.exe recording in a text file after the copying terminati; (5) the copied file deleti; (6) system restart. The whole procedure was repeated 100 times. test π computing Π computing to 8,388,608 (8M) decimal points was tested. The SystemStabilityTester programme was used for the computing, using two n-cooperating links and Gauss Legendre algorithm. The sequence of commands was as follows: (1) system boot up ISBN:

4 and user login; (2) 30-secd waiting till the system procedures stabilizati (3) π computing; (4) the computing output recording in a text file after the copying terminati; (5) system restart. The test was repeated 100 times and the results were recorded in two forms, directly from the calculating programme and from Timeit.exe. HDD test Copying of a randomly generated 1 GB file was tested. The sequence of commands was as follows: (1) system boot up; (2) 90-secd waiting till the system procedures stabilizati; (3) start of the file copying after logging- as a parameter of Timeit.exe; (4) output recording in a text file after the copying terminati; (5) the copied file deleti; (6) system restart. The test was repeated 100 times and Timeit.exe was used both for values recording and measurement. NIC test After the network interface was cfigured and the network put into operati, we tested the durati of respse the network layer of the ed system. Ping [7], a generally known programme, was used for testing. The requests were sent from an external source and were recorded in a file. The request was sent 100 times and the result was recorded. 3 Measured data As we mentied above, Windows 7 32b is the primary operating system at FIM UHK. Therefore, this system was chosen to be the operating system (OS). The OS was tested by means of the same series of tests as the virtualized machines and its values were used as the reference es. It is called below in the text. Windows 7 32b was the ed systems. VirtualBox, VirtualPC and Player were the virtualizati envirment. Three tested envirments thus originated, called for systems virtalised VirtualBox, for systems virtualised VirtualPC and finally for the systems virtualised Player. NIC test In this test, we measured the time respse from the local server to the virtualized NIC by means of the Ping programme. The server and the were cnected directly by means of a gigabyte crossover UTP 5E cable. The results are shown in secds. Average 0,3624 0,4903 0,4179 0,1884 deviati 0,007 0,107 0,055 0,013 Variance 0,000 0,011 0,003 0,000 Maximum 0,383 1,09 0,79 0,231 3rd Quartile 0,366 0,516 0,437 0,193 Median 0,363 0,479 0,4185 0,185 1st Quartile 0,359 0,448 0,395 0,181 Minimum 0,337 0,285 0,319 0,171 Table 1 Results of the NIC test It is evident from the measured values that the least time delays were shown during the NIC test by the virtualized system. showed better results virtualizati processing of the hypervisor. The results are presented in the table above this part of the paper. test π computing The test was aimed to the computing performance of the virtualized operating system. Data acquired by the SystemStabilityTester programme in all tested envirments were used. The values are shown in secds. Average 462, , , ,4244 deviati 31,944 1,709 3,929 0,474 Variance 1020,417 2,920 15,436 0,225 Maximum 613, , , ,219 3rd Quartile 456, , , ,643 Median 455, , , ,308 1st Quartile 450, , , ,140 Minimum 448,42 443,97 483,64 182,46 Table 2 Results of the test π computing It follows from the measured values that Windows VirtualPC showed better results in virtualizati of both operating systems in the tests focused to computing performance. encrypti test ISBN:

5 In the encrypti-focused tests, the time required for a randomly generated 1 GB file encrypti was measured. A 256b AES encrypting algorithm was used for the encrypting. The values are shown in secds. The encrypti results were not stored to avoid the influence of the data recording speed. Average 32,441 20,982 26,523 12,428 deviati 4,375 0,790 1,374 1,085 Variance 19,138 0,624 1,887 1,177 Maximum 41,109 22,221 32,506 14,164 3rd Quartile 35,390 21,300 26,846 13,498 Median 31,656 21,000 26,227 11,559 1st Quartile 29,718 20,289 26,015 11,540 Minimum 24,78 17,62 18,10 11,51 Table 3 Results of the encrypti test These tests also show that in use, virtualizati by means of Windows VirtualPC is more effective. HDD test In this test, we measured the durati of the data recording and reading a virtualized 1 GB HDD. The values are shown in secds. Average deviati 47,698 32,028 32,588 27,933 2,263 0,688 1,174 1,554 Variance 5,123 0,474 1,377 2,415 Maximum 58,531 33,408 37,231 32,510 3rd Quartile 48,703 32,797 33,057 28,618 Median 48,070 31,915 32,604 27,979 1st Quartile 46,890 31,443 31,625 27,338 Minimum 41,38 30,94 30,94 24,91 Table 4 Results of the HDD test Marked differences were measured during the recording and reading testing in Windows Virtual PC,Oracle VirtualBox and VMWare Player. The measured results suggest that Oracle VirtualBox access to the virtualized HDD is markedly quicker. In the Windows 7 operating system virtualizati, the results do not differ markedly although, when comparing the measured values, Windows VirtualPC is quicker in a n-significant extent. 4 Evaluati Several cclusis can be made from the results of our measurements. The results are very favourable for the needs of the envirment from which the request for such research came. We can say that despite evident differences between the individual tools, both are usable very well and meet the educatial requirements. Both virtualizati tools can be used for training of the tasks related to the administrati and protecti the operating system and computer networks. In both cases, the differences between the native and virtual machine reached no more than the multiples of the reference values measured the system. These facts are shown in Graph 1. It shows a comparis of the differences of values related to the reference values; the system result is csidered to be 100%. If the performance requirements were stressed, the Microsoft soluti should be preferred. On the other side, the rest two virtualizati tools indicate the useful set of performance results which can be adopted for the educatial purpose. Windows7 VirtualPC VirtualBox Windows 7 HDD 47, , , ,9329 Encrypting Computing PI 32, , , , , , , ,4243 NIC Echo 0,3624 0,4903 0,4179 0,1883 Tab. 5 Final Comparis Virtual PC Virtual Box HDD 4,0947 4, ,7650 Encrypting 8, , ,0129 Computing PI 264, , ,1449 NIC Echo 0,3019 0,2296 0,1740 Tab. 6 Differences from the average reference values ISBN:

6 References: [1] BHADANI, A. Cloud Computing and Virtualizati. 1. Saarbrucken : VDM Verlag Dr. Muller Aktiengesellschaft & Co. KG, s. ISBN [2] MARSHALL, D., The Rise of Virtual Systems and Virtualizati (-line), Virtualizatisdefrag.com Editors, 2009 [cit ]. Available from: < istory-of-virtualizati/index.php>. [3] Oracle. VirtulaBox.org [line]. 2008, 2010 [cit ]. VirtulaBox Documentati. Available from WWW: < >. [4]. Vmware.com [line] [cit ]. Player Release Notes. Available from WWW: < c/releasenotes_player314.html>. [5] Microsoft. Microsoft.com [line] [cit ]. Windows Virtual PC. Available from WWW: < [6] Advanced Encrypti. In Wikipedia : the free encyclopedia [line]. St. Petersburg (Florida) : Wikipedia Foundati, January 2011, last modified January 2011 [cit ]. Dostupné z WWW: < pti_>. [7] STANEK, W. R. Windows 7 Administrator's Pocket Csultant. 1. Redmd : Microsoft Press,U.S., s. ISBN [8] TSATIRIS, L. ; ANASTASIADIS, P. System Stability Tester [line]. 2007, 2011 [cit ]. System Stability Tester. Available from WWW: < [9] Gauss-Legendre algorithm. In Wikipedia : the free encyclopedia [line]. St. Petersburg (Florida) : Wikipedia Foundati, June 2008, last modified April 2011 [cit ]. Available from WWW: < 93Legendre_algorithm>. ISBN:

7 Graph.1 Final comparis ISBN: