This diploma thesis offers an overview of hypervisors and methods how they manage memory. Next part describes Memory overcommit Manager, design policies for more efficiet utilization of memory with memory ballooning. There are also description and implementation of newly created MoM Simulator. Purpose of this tool is to easily verificate the policies without running on a real hypervisor. In the latest part there are a description and a design of another new tool for managing constants. It allows applying policies on each virtual machine intedependently.

abstract: The increasing usage of smart-phones and mobile devices in work environment and IT industry has brought about unique set of challenges and opportunities. ARM architecture in particular has evolved to a point where it supports implementations across wide spectrum of performance points and ARM based tablets and smart-phones are in demand. The enhancements to basic ARM RISC architecture allow ARM to have high performance, small code size, low power consumption and small silicon area. Users want their devices to perform many tasks such as read email, play games, and run other online applications and organizations no longer desire to provision and maintain individual’s IT equipment. The term BYOD (Bring Your Own Device) has come into being from demand of such a work setup and is one of the motivation of this research work. It brings many opportunities such as increased productivity and reduced costs and challenges such as secured data access, data leakage and amount of control by the organization. To provision such a framework we need to bridge the gap from both organizations side and individuals point of view. Mobile device users face issue of application delivery on multiple platforms. For instance having purchased many applications from one proprietary application store, individuals may want to move them to a different platform/device but currently this is not possible. Organizations face security issues in providing such a solution as there are many potential threats from allowing BYOD work-style such as unauthorized access to data, attacks from the devices within and outside the network. ARM based Secure Mobile SDN framework will resolve these issues and enable employees to consolidate both personal and business calls and mobile data access on a single device. To address application delivery issue we are introducing KVM based virtualization that will allow host OS to run multiple guest OS. To address the security problem we introduce SDN environment where host would be running bridged network of guest OS using Open vSwitch . This would allow a remote controller to monitor the state of guest OS for making important control and traffic flow decisions based on the situation. / Dissertation/Thesis / Masters Thesis Computer Science 2015

Virtual Environments have transformed over the years the way software is built and distributed. The recent growth of services such as Amazon EC2 or Google Cloud is representative of this trend and encourages developers to build software intended for virtual environments like virtual machines or containers. Despite all the benefits that virtualization brings (isolation, security, energy efficiency, stability, portability, etc.), the extra layer of software between the virtual environment and the hardware, called the hypervisor, increases the complexity of a system and the interpretation of its metrics. In this paper, we explore the situation of software performing latency measurements from a virtual environment. This is an example of a use-case where latency from the hypervisor could lead to measurable noise on the virtual environment if the hypervisor makes our environment wait for resources for milliseconds. To solve this problem, we propose an algorithm that will filter out this noise from computed metrics from the virtual environment. This algorithm was developed studying correlation between those metrics and hypervisor-induced latency spikes. We also try to be hypervisor agnostic which means that this work stays relevant whether a virtual environment is deployed locally or on a Cloud Service with different (and constantly evolving) hypervisor technologies. This research gives an overview of hypervisor technologies and how latency can appear when executing processes on virtual environments. As we will see, computing the metric and running the algorithm make network quality measurements from virtual environments more reliable and can explain unexpected latencies. / Virtuella miljöer(virtual environments) har under åren förändrat hur mjukvara(software) byggs och distribueras. Den senaste tidens tillväxt av tjänster som Amazon EC2 eller Google Cloud är representativ för denna trend och uppmuntrar utvecklare att bygga programvara avsedd för virtuella miljöer som virtuella maskiner eller behållare. Trots alla fördelar som virtualisering ger (isolering, säkerhet, energieffektivitet, stabilitet, portabilitet, etc.), ökar det extra lagret av mjukvara mellan den virtuella miljön och hårdvaran, kallad hypervisor, komplexiteten hos ett system och tolkning av dessa måtvärden. I denna artikel utforskar vi situationen för programvara som utför latensmätningar från en virtuell miljö. Detta är ett exempel på ett användningsfall där latens från hypervisorn kan leda till mätbart brus i den virtuella miljön om hypervisorn får vår miljö att vänta på resurser i millisekunder. För att lösa detta problem föreslår vi en algoritm som kommer att filtrera bort detta brus från beräknade mätvärden från den virtuella miljön. Denna algoritm utvecklades för att studera korrelationen mellan dessa mätvärden och hypervisor-inducerade latensspikar. Vi försöker också vara hypervisoragnostiska vilket innebär att detta arbete förblir relevant oavsett om en virtuell miljö distribueras lokalt eller på en molntjänst med olika (och ständigt utvecklande) hypervisorteknologier. Denna forskning ger en översikt över hypervisorteknologier och hur latens kan uppstå när processer körs i virtuella miljöer. Som vi kommer att se gör beräkning av måtten och körning av algoritmen mätningar av nätverkskvalitet från virtuella miljöer mer tillförlitliga och kan förklara oväntade latenser. / Les environments virtuels transforment depuis des années la manière de développer et distribuer du logiciel. La récente croissance de services comme Amazon EC2 ou Google Cloud reflète bien cette tendance et encourage les développeurs à construire du logiciel déployable sur des environnements virtuels comme des machines virtuels ou des conteneurs. Malgré tous les bénéfices que la virtualisation apporte (isolation, sécurité, efficacité énergétique, stabilité, portabilité, etc.), la couche logiciel supplémentaire entre l’environnement virtuel et le hardware, appelée hyperviseur, augmente la complexité d’un système et l’interprétation de ces métriques. Dans ce mémoire de projet de fin d’études, nous explorons la situation où un logiciel effectue des tests de latence depuis un envirronnement virtuel. Cette situation est un exemple d’un cas d’utilisation où la latence introduite par un hyperviseur peut mener à un bruit mesurable si l’hyperviseur fait attendre notre environnement dans l’ordre de grandeur de la milliseconde. Pour résoudre ce problème, nous proposons un algorithme qui filtre ce bruit à partir de métriques calculées directement depuis l’environnement virtuel. Cet algorithme est dévelopé en étudiant la corrélation entre nos métriques et une latence dite "hypervisor-induced". Cette approche permet donc une grande flexibilité dans la technologie sous-jacente de l’hôte puisque celui-ci peut utiliser des hyperviseurs différents ou même faire partie d’un service Cloud sans que notre solution en soit impactée. Ce mémoire donne aussi un aperçu de la technologie derrière un hyperviseur et comment de la latence peut s’introduire dans l’exécution d’un processus dans un environnement virtuel.

Today's cloud landscape has evolved computing infrastructure into a dynamic, high utilization, service-oriented paradigm. This shift has enabled the commoditization of large-scale storage and distributed computation, allowing engineers to tackle previously untenable problems without large upfront investment. A key enabler of flexibility in the cloud is the ability to transfer running virtual machines across subnets or even datacenters using live migration. However, live migration can be a costly process, one that has the potential to interfere with other applications not involved with the migration. This work investigates storage interference through experimentation with real-world systems and well-established benchmarks. In order to address migration interference in general, a buffering technique is presented that offloads the migration's read, eliminating interference in the majority of scenarios.

鑒於台灣近二十年來PC產業所面臨微利化趨勢以及中國大陸崛起所擁有之低勞工成本優勢，在IT產業一片哀鴻遍野中，思考如何突破現狀而轉型至利基型之工業電腦領域，進而找出產業未被滿足之應用商機，並加強技術研發及行銷策略。 本論文以尚處於產業發展初期，年複合成長率達雙位數成長之KVM切換器(Keyboard、Video、 Mouse Switch)作為研究的課題，探討台灣資訊產業如何運用本身有限資源投入利基型應用領域，希能為台灣資訊產業帶來拋磚引玉之效果而略盡棉薄之力。 本研究是採用質化分析，研究方法是使用探索性研究之次級資料分析與個案研究，目的是在解釋一種實證性的探究，以實務的現象，加上個案說明，以4C理論架構，逐項分析比較以及歸納。以此研究方法與架構，探討台灣KVM切換器事業如何跨越門檻擠進系統解決方案市場國際大廠壟斷局勢，以及穩居眾多小廠覬覦之中低階產品市場所面臨各項行銷交換成本時所應採取的策略。 最後由於KVM切換器事業尚屬於起飛階段，時間不長、代表性廠商數量不多且個別公司的專屬資料蒐集不易、產業次級統計資料也不足，因此未來後續研究者可考慮朝量化的研究進行更深入之探討。

The theoretical part of this thesis is devoted to familiarization with the technology of cloud computing, virtualization technology, data storage problems and Petri nets. Followed by the practical part, the first part discusses the various technologies which are VMware ESX, Citrix Xen, Hyper -V, KVM and oVirt. The following part is a summary of the characteristics of each technology and an output of this summary is a decision tree which is intended to help to select the appropriate virtualization technology. The second part is dedicated to the implementation of an application used for storing data in the database depending on the sensitivity of data. The thesis includes the final economic evaluation and discussion as well.

Made available in DSpace on 2014-06-12T15:58:06Z (GMT). No. of bitstreams: 2 arquivo3252_1.pdf: 2382561 bytes, checksum: c2a06bbc48d03850db39ab0f6ef2859e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho apresenta uma proposta para gerenciamento e monitoramento de redes virtuais através da adaptação do Nagios, uma ferramenta de gerência e monitoramento amplamente utilizada em datacenters por administradores de rede. Esta adaptação foi implementada através da criação de um plug-in que coleta dados relevantes de switches virtuais realizando inferências de estados de disponibilidade destes switches. Para verificação da usabilidade do plug-in, foi criada uma rede virtual utilizando o software de padrão aberto Openflow e OpenvSwitch em conjunto com o NOX, além da criação de máquinas virtuais sobre o virtualizador KVM com o auxílio da biblioteca libvirt para criação das máquinas virtuais e interfaces virtuais

Context. Virtualization technologies have been extensively used in various cloud platforms. Hardware replacements and maintenance are occasionally required, which leads to business downtime. Live migration is performed to ensure high availability of services, as it is a major aspect. The performance of live migration in virtualization technologies directly impacts the performance of cloud platforms. Hence comparison is performed in two mainstream virtualization technologies, container and hypervisor based virtualization. Objectives. In the present study, the objective is to perform live migration of hypervisor and container based virtualization technologies, Kernel Virtual Machine (KVM) and Linux Containers (LXC) respectively. Measure and compare the downtime, total migration time, CPU utilization and disk utilization of KVM and LXC during live migration. Methods. An initial literature is conducted to get in-depth knowledge about live migration in virtualization technologies. An experiment is conducted to perform live migration in KVM and LXC. The live migration process is performed when 100 % and 66% workloads are being generated to Cassandra present in virtual machine and container. The performance of live migration in KVM and LXC is measured in terms of CPU utilization, disk utilization, total migration time and downtime. Results. Based on the obtained results from the experiment, graphs are plotted for the performance of KVM and LXC during live migration. The results indicated that KVM has better CPU utilization when compared to LXC. However, downtime, total migration time and disk utilization of LXC are relatively better than KVM. From the obtained results, mean and standard deviation are calculated. Box plotting for downtime and total migration time is performed to illustrate difference between KVM and LXC. The measurable difference between KVM and LXC is calculated using Cohen’s d effect size for downtime, total migration time, CPU and disk utilization. Conclusions. The present study concludes that no single hypervisor has better performance when considering all performance metrics. While LXC has better performance when considering downtime, total migration time and disk utilization. However, KVM performs better when CPU usage is considered.

This diploma thesis contains detailed design of high-performance cluster, primarely focused for parallel computing in Octave application. Each of component of this cluster is described along with instructions for installation and configuration. Cluster is based on GNU/Linux operating system and Message Parsing Interface. Design alllows implementation of this cluster in computers of schoolroom with active lessons.

This work deals with possibilities of administration of virtual machines (mainly from the developer's point of view) and available methods for automatic installation of GNU/Linux distributions. First part contains the information about virtualisation technologies and possibilities to configure them with a libvirt library. The definition and specification of each part of virtualisation environment (virtual machines, disks, networks) using XML is described. Further more the possibilities of automatic installation of Linux distributions based on RedHat and Debian considering the virtualisation environment are discussed. The possibility of copying an existing disk with installed system is also mentioned. In a practical part a server application for control and management of virtual machines including automatic installation of operating system is proposed and realised.