we are required to refer to the research paper and discuss the following:

A. Technically explain any two types of Virtualisation techniques and elaborate the

technicality associated with their functions. (15 Marks)

Note: please dont copy things from the internet because they are checking the plagarism. Answer must be typed.Thanks

A Study On Virtualization Techniques And Challenges In Cloud Computing Duraira), M, Kannan P Abstract: Cloud computing is a modern technology that increase application potentialities in terms of functioning, elastic resource management and collaborate execution approach. The central part of cloud computing is virtualization which enables industry or academic IT sources through on- demand allocation dynamically. The resources have different forme such as network server storage, aplication and client. This paper focus as on how virtualization tips to improve elasticity of the resources in cloud computing environment. In addition to this paper gives a detailed review on en scuros virtualization techniques, challenges and future research direction Index Terma: challenges, doud computing, elasticity. hypervisor Wirtualization 1 INTRODUCTION Virtualization [4] [5] [6] [7] is a technique which allows to Cloud computing refers to a colaborative IT (Information creates abstract layer of system resources and hides the Technology) environment, which is planned with the intention complexity of hardware and software working environment. of measurable and remotely purveying scalable IT resources The virtualization provides hardware independence, solation for effective and efficient utilization National Institute of of guest operating system and encapsulation of entire virtual Standards and Technology (IST) has given a definition (1) for machine grouped in a single file. Virtualization commonly Cloud computing which says that "Cloud Computing is a implemented with hypervisor 18 19 technology, which is a model for enabling convenient, on-demand network access to software or firmware elements that can virtualizes system a shared pool of configurable computing resources (eg. resources. The remaining part of this paper is formed as networks, servers, storage, applications, and services) that follows: Section | gives an introduction to the cloud can be rapidly provisioned and released with minimal computing technology Section presents various management effort or service provider interaction". Five virtualization techniques in cloud computing environment. essential characteristics of cloud computing listed by NIST are Section IV describes the types of virtualization Challenges on-demand self-service, broad network access, resource and analysis of open source based hypervisor models for pooling, rapid elasticity and measured service. Mobile cloud cloud are explained in section V. Section V concludes the computing is the computing which refers to anytime, anywhere paper accessibility to applications and data through intemet using mobile devices. Traditional computing resources are stored in 2 VIRTUALIZATION FOR CLOUD an individual device and accessed by an authenticated user. Virtualization [10] [11] technology diverts the human's In Cloud compuing, resource are stored in centralized mamer perspective for utilizing IT resources from physical to logical. and accessed on demand basis. In recent days, mobile The goal of virtualization is to collaboratively utilize the IT devices and subsequent mobile computing become an resources such as storage processor and network to imperative component in cloud computing Internet made the maximum level and to reduce the cost of IT resources which possibilities of accessing applications and data from anywhere can be achieved by combining multiple Idle resources into at any time. According to Juniper research R), the mobile shared pools and creating different virtual machines to perform users and enterprise market for mobile cloud based various tasks simultaneously. The resources can be allocated applications worth are expected to increase to $9.5 billion by or altered dynamically. User should be conscious of basic 2014. Aepona 3] describes that MCC Mobile Cloud techniques such as emulation, hypervisor, full, para and Computing) as a new paradigm for mobile applications hardware assisted Virtualization while using virtualization in whereby the data processing and storage are moved from the cloud computing environment mobile devices to powerful and centralized computing platforms located in clouds. These centralized applications Emulation: It is a virtualization technique which converts the are then accessed over the wireless connection based on a behavior of the computer hardware to a software program and thin native client or web browser on the mobile devices. lies in the operating system layer which lies on the hardware Emulation provides enormous flexibility to guest operating system but the speed of translation process is low compared to hypervisor and requires a high configuration of hardware resources to run the software [12]. Assistant Professor School of Computer Science Engineering and Applications Bharathidasan University, India Email: duraraj.bdu@gmail.com Research Scholar, School of Computer Science, Engineering and Applications Bharathidasan University. India Email: kannancsbd@gmail.com Virtual Machine Monitor or Hypervisor: A software layer that can monitor and virtualize the resources of a host machine conferring to the user requirements (13) R is an intermediate layer between operating system and hardware Basically, hypervisor is classified as native and hosted [14]. The native based hypervisor runs directly on the hardware whereas host based hypervisor runs on the host operating system. The software layer creates virtual resources such as virtualization [18] that provides multiple ways to run an CPU, memory, storage and drivers. application which is not in traditional manner. In this technique an isolated virtualized environment or partitioning technique is Para Virtualization: This technique provides special used to run an application hypercalls that substitutes the instruction set architecture of host machine. It relates communication between hypervisor Storage Virtualization: It creates the abstraction of logical and guest operating system to improve efficiency and storage from physical storage. Three kinds of data storage perfomance Accessing resources in para virtualization (15) are used in virtualization, they are DAS (Direct Attached is better than the full virtualization model since all resources Storage), NAS (Network Attached Storage) and SAN (Storage must be emulated in full virtualization model. The drawback of Area Network). DAS is the conventional method of data this technique is to modify the kernel of guest aperating storage where storage drives are directly attached to server system using hypercalls. This model is only suitable with open machine NAS is the shared storage mechanism which source operating systems. connects through network. The NAS is used for file sharing. device sharing and backup storing among machines SAN IS Full Virtualization: Hypervisor creates isolated environment a storage device that are shared with different server over a between the guest or virtual server and the host or server high accelerate network. Hypervisor is the software package hardware, Operating systems directly access the hardware that controls working access to the physical hardware of host controllers and its peripheral devices without cognizant of machine. There are two kinds of hypervisor models as hosted virtualized environment and requirement modifications (16) and bare metalative. Hosted hypervisor instance operates on top of the host operating system whereas bare metal based 3 VIRTUALIZATION TYPES hypervisor operates directly on the hardware of host machine There are three major types of virtualization such as Server Fig 2 shows the comparison between traditional, bare metal virtualization, Client virtualization and Storage virtualization, and hosted models. The architecture and categorization of virtualization techniques are illustrated in Fig 1 Minaliarita Types 1 APPLICATION ALICATION APLICATION Serve Delitop Clicut Song Minuinin) Vinuindice Vitalization OPERATING SYSTEM OPERATING SYSTEM MYRRVISOR Full hun He Lecal Applicad DAS SAN NAS HARDWARE Asted led level on levd OLANTEM 1 HARDWARE US Fig 1 Virtualization types Server Virtualization: In server virtualization, single server Fig 2 Traditional Model Vs Bare Mode Vs Hosted Model performs the task of multiple servers by portioning out the resources of an individual server across mull-environment. Majority of obstacles arises in the acceptance and The typervisor layer allows for hosting multiple applications development of virtualization and cloud computing are and operating systems locally or remotely. The advantages of concerned to the basic management aspects such as data virtualization include cost savings, lower capital expenses, leakage, virtualization security threats, data remanense issue, high availability and efficient use of resources privacy and elastic resource management, Client Virtualization. This client virtualization technogy Data Leakage: Organizations are in high risk of data leakage makes the system administrator to virtually monitor and when an employee secures the access ts data stored in update the client machines like workstation desktop, laptop cloud system. Data leakages [19] are happens through and mobile devices it improves the client machines hacking data location, securing remote access, third party management and enhances the security to defend from storage and unsecure multitenant environment in typervisor hackers and cybercriminals. There are three types of client level Cloud provider or broker can enhance the prevention virtualization (17). First, remote or server hosted virtualization and detection mechanism and implement the collaborative which is hosted on a server machine and operated by the security policy in hypervisor level to protect data from data client across a network. Second, local or client hosted leakage virtualization in which the secured and virtualized operating environment runs on local machine Third, application 148 Virtualization Security Threats: Security threats [20] in destruction time policy among cloud provider, broker and user virtualization are classified into virtual machine threat, once the data reach their expiration period. Third concern is hypervisor threat, virtual infrastructure and virtual network data breaches which studies on how data breaches occur and threat . The virtual machine threat surfaces while processing who are going to take responsibility if data breach occurs in status of virtual machine, software updates, resource cloud. When a user opt for using cloud services, the user contention, patching and virtual machine conurbation should read the terms and conditions thoroughly before Hypervisor threat rivets Virtual Machine-Based Rootkit prompt to cloud. The fourth concern is on regular auditing and (VMBR) attack and Blue Pe Attack 21] where hypervisor monitoring policies. Cloud clients should constantly monitor / plays the vital role of Virtualization Virtual infrastructure audit the activities of cloud service provider to ensure their threats are concerted on physical access threat and single stakeholder personal information will not be leaked while cloud point of control threat. Virtual network threats can be resources are sharing with others. effectively addressed by the security tools of intrusion detection, prevention mechanism, virtual switches and Elastic Resource Management: Cloud computing system networks conferring to the requirements. produce new disputes because of system clusters and high volume data generated by these systems. In order to work Data Remanence issue [22]: Once the life ime of data is effective elastic resource management, we need to look at the used, then it will be deleted in secure manner and cannot be issues such as resource allocation, resource provisioning. recovered by malicious users. In traditional manner, company resource mapping and resource adaptation [24][25][26][27], has all control of their servers which can be overwrite the used Cloud Services encounter issues on the requirements of data. But in cloud, the end user/cloud users are not given service level elasticity and availability. The high performance Secure delete access to the cloud provider physical device. of cloud can be achieved through implementing effective Cloud provider should focus to ensure no data will be elastic resource management techniques as a result user recovered by any malicious users. could get efficient services from service providers. Table 1 represents the virtualization techniques from open source Privacy: Privacy [23] becomes a major concern among cloud providers like Redhat, Citrix systems, Oracle, Openvz, Linux- users data which is stored in the data center of cloud service vserver and Proxmox in the table, we compare different providers physically located in different places. In doud, there hypervisor models with different virtualization techniques. As are some circumstances which lead to the privacy threats. We discussed in earlier sections, virtualization is the concept of First, the storage issues that surface when user store data in creating virtual resources from physical resources such as multiple storage locations which are hidden from the user and operating systems, network and storage components. have the possibilities of transferring data without owner's permission Second major concern is to ensure the TABLE 1 COMPARISON OF OPEN SOURCE BASED HYPERVISOR VIRTUALIZATION TYPES S. No Hypervisor Name Company Hypervisor Model Full Virtualization Types Para Hardware Assisted No No Operating System 1 KVM Red Hat Hosted Yes No 2 XEN Citrix systems, inc Bare Metal No Yes Yes No Virtualbox Oracle Hosted No Yes Yes No OpenVZ Linux OpenVZ Hosted No No No Yes 5 Linux-Vserver Linux-Vserver Hosted No No No Yes Proxmox VE Proxmox Bare Metal Yes No No Yes 5 CONCLUSION AND FUTURE WORK Proc. Int Cloud and Service Computing (CSC) Conf, 2011, This paper discussed various virtualization techniques, Pp. 321-329 virtualization types, hypervisor techniques and challenges in cloud computing system to reduce it costs and effective [11] W. Dawoud. I. Takouna, and C. Meinel, "Infrastructure as utilization of cloud resources such as rapid elastic provisioning a service security Challenges and solutions", in Proc. of virtual machines, elastic application programming model in Informatics and Systems (INFOS). 2010 The 7th addison, the virtualization techniques get universal support International Conference on, 2010, pp. 1-8. when users consider elastic resource management issues and security issues before moving into cloud. In future, we aim to [12] Calheiros RN, Buyya R, De Rose CAF, Building an develop new policies, framework and techniques to maintain automated and self-configurable emulation testbed for grid elastic resources and data availability, as a result, the applications Software: Practice and Experience, April performances of cloud services could steps into next higher 2010: Vol 40(5), pp. 405-429. level. This study paper discussed various issues pertaining to cloud services which can be used to design strong framework [13] A. Whitaker, M. Shaw, S. D. Gribble, "Denal: Lightweight for effective elastic resource management in cloud. virtual machines for distributed and networked applications". Tech. rep. (Feb. 08 2002). REFERENCES [1] P. Mell, T. Grance. "The NIST Definition of Cloud (14) IBM, "IBM systems virtualization", version 2 release 1, Computing'. National Institute of Standards and http://publib boulder.ibm.com/infocenter/eserver/1/2/opic Technology Information Technology Laboratory, leicayeicay.pdf (2005) Technical Report Version 15, 2009. [15] P. Batham, B. Dragovic, K Fraser, S. Hand, T. Harris, A. 12] S. Perez, "Mobile cloud computing $9.5 billion by 2014, HO, R. Neugebauer, I. Pratt and A. Warfield, "Xen and the http://exoplanet.eu/catalog php, 2010. art of Virtualization", In SOSP 03. Proceedings of the nineteenth ACM symposium on operating systems [3] White Paper, Mobile Cloud Computing Solution Brief, principles (New York, NY, USA, 2003). ACM Press. pp. AEPONA. November 2010 164-177 141 B. Loganayagi, S. Sujatha, "Creating virtual platform for [16] Asma ben letaita, Amed haj. Maha Jebalia, Sami cloud computing" IEEE International Conference on Tabbane. "State of the Art and Research Challenges of Computational Intelligence and Computing Research new services architecture technologies: Virtualization (ICCIC 2010), 28-29 Dec, 2010, pp. 1-4 SOA and Cloud Computing". Intematonal Joumal of Grid and Distributed Computing 3(4), December 2010, 69-88. 151 Dawel Sun, Guiran Chang, Qiang Guo. Chuan Wang, Xingwei Wang. "A Dependability Model to Enhance [17] IBM Virtual Infrastructure Access Service Product Security of Cloud Environment Using System-Level https://www. Virtualization Techniques". First International Conference 935.ibm.com/services/augts.bdfend 3005usend, on Pervasive Computing, Signal Processing and Applications (PC SPA), 2010, pp.305-310 [18] B. Siddhisena, Lakmal Wruasawithana, Mithia Mendis, *Next generation muti tenant virtualization cloud [6] Karen Scarfone, Murugiah Souppaya, and Paul Hoffman, computing platform. In: Proceedings of 13th Intemational conference on "Guide to Security for Full Virtualization Technologies", advanced communication Special Publication 800-125, National Institute of technology(ICACT), vol. 12, no.3, 2011. p.405-10. Standards and Technology (IST), 2011, [19]c. Almond, "A Practical Guide to Cloud Computing 17 P. Barham, B. Dragovic, K. Fraser, S. Hand, T. Harris, A. Security, 27 August 2009 Ho, R. Neugebauer, I. Pratt , A Warfield, "Ken and the art 120 Timur Mirzoev, Baijian Yang. "Securing Vrualized of virtualization", in: Proc. 19th ACM Symposium on Operating Systems Principles, SOSP 2003, Bolton Datacenters". International Journal of Engineering Landing, USA, Oct. 2003 Research & Innovation, vol. 2, no. 1Spring 2010 (8) Joanna Rutkowska and Alexander Tereshkin, "Bluepiling 1211J. Rutkowska, "Subverting Visa Kernel For Fun and ne Xen Hypervisor", Xen Owning Trilogy part II Black Hat Profit". Aug 2006, Black Hat conference USA, aug 2008 http://blackhat.com/presentations/bh-usa-06/BH-US-06- Rutkowska.pdf 19] Samuel T. King, Peter M. Chen, Yi min Wang, Chad Verbowski, Helen J. Wang, and Jacob R.Lorch, Subvirt: 122] Tim Mather, Subra Kumaraswamy, Shahed Latif,"Cloud Implementing Malware with Virtual Machines". In IEEE Security and Privacy. An Enterprise Edition on Risks and Symposium on Security and Privacy, 2006. Compliance (Theory in Practice). O Rely Media, Sep.2009 ISBN: [10] 2. Pan, Q. He, W. Jiang Y Chen, and Y. Dong, 9780596802769 http://arcilly.com/catalog/9780596802776 "Nestcloud: Towards practical nested virtualization in