7. Virtualisation Fundamentals

Foundation Course on Information Technology Outsourcing UNIT - 7: VIRTUALIZATION FUNDAMENTALS Structure 7.0 Learning Objectives 7.1 Introduction 7.2 Basics of Virtualization 7.3 Microsoft Virtualization Basics 7.4 Summary 7.5 Learning Activity 7.6 Glossary 7.7 References 7.0 Learning Objectives After studying this unit, you will be able to • Relate to the concept of Virtualization • Recall History of Virtualization • Identify Features, Vendors • Use Microsoft Virtualization products: ▪ Hyper-V ▪ ESX host ▪ VCentre 7.1 Introduction Today’s x86 computer hardware was designed to run a single operating system and a single application, leavingmost machines vastly underutilized. Virtualization lets you run multiple virtual machines on a single physicalmachine, with each virtual machine sharing the resources of that one physical computer across multipleenvironments. Different virtual machines can run different operating systems and multiple applications on thesame physical computer. While others are leaping aboard the virtualization bandwagon now, VMware is themarket leader in virtualization. Our

Foundation Course on Information Technology Outsourcing technology is production-proven, used by more than 170,000 customers, including 100% of the Fortune 100.Improve the efficiency and availability of IT resources and applications through virtualization. Start by eliminating the oldone server, one application‖ model and run multiple virtual machines on each physical machine. Free your IT admins from spending so much time managing servers rather than innovating. About 70%of a typical IT budget in a non-virtualized datacenter goes towards just maintaining the existing infrastructure, with little left for innovation. An automated datacenter built on the production-proven VMware virtualization platform lets you respond tomarket dynamics faster and more efficiently than ever before. VMware vSpheredelivers resources, applications even servers when and where they’re needed. VMware customers typically save 50-70% on overall IT costsbyconsolidating their resource pools and delivering highly available machines with VMware vSphere. • Run multiple operating systemson a single computer including Windows, Linux and more. • Let yourMac run Windows creating a virtual PCenvironment for all your Windows applications • Reduce capital costsby increasingenergy efficiencyand requiring less hardware while increasing yourserver to admin ratio • Ensure yourenterprise applicationsperform with the highest availability and performance • Build upbusiness continuitythrough improveddisaster recoverysolutions and deliver high availabilitythroughout the datacenter • Improveenterprise desktop management & controlwith faster deployment of desktops and fewer supportcalls due to application conflicts 7.2 Basics of Virtualization Virtualization is the \"creation of a virtual (rather than actual) version of something, such as a server, a desktop, a storage device, an operating system or network resources”. In other words, Virtualization is a technique, which allows to share a single physical instance of a resource or an application among multiple customers and organizations. It does by assigning a logical name to a physical storage and providing a pointer to that physical resource when demanded. Creation of a virtual machine over existing operating system and hardware is known as Hardware Virtualization. A Virtual machine provides an environment that is logically separated from the underlying hardware. The machine on which the virtual machine is going to create is known as Host Machine and that virtual machine is referred as a Guest Machine.

Foundation Course on Information Technology Outsourcing Types of Virtualization: • Hardware Virtualization. • Operating system Virtualization. • Server Virtualization. • Storage Virtualization. Hardware Virtualization: When the virtual machine software or virtual machine manager (VMM) is directly installed on the hardware system is known as hardware virtualization. The main job of hypervisor is to control and monitoring the processor, memory and other hardware resources. After virtualization of hardware system, we can install different operating system on it and run different applications on those OS. Usage: Hardware virtualization is mainly done for the server platforms, because controlling virtual machines is much easier than controlling a physical server. 2) Operating System Virtualization: When the virtual machine software or virtual machine manager (VMM) is installed on the Host operating system instead of directly on the hardware system is known as operating system virtualization. Usage: Operating System Virtualization is mainly used for testing the applications on different platforms of OS 3) Server Virtualization: When the virtual machine software or virtual machine manager (VMM) is directly installed on the Server system is known as server virtualization. Usage: Server virtualization is done because a single physical server can be divided into multiple servers on the demand basis and for balancing the load. 4) Storage Virtualization: Storage virtualization is the process of grouping the physical storage from multiple network storage devices so that it looks like a single storage device. Storage virtualization is also implemented by using software applications. Virtualization plays a very important role in cloud computing technology, normally in the cloud computing, users share the data present in the clouds like application etc, however, with the help of virtualization users shares the Infrastructure.The main usage of Virtualization Technology is to provide the applications with the standard versions to their cloud users, suppose if the next version of that application is released, then cloud provider has to provide the latest version to their cloud users and practically it is possible because it is more expensive. To overcome this problem, we use basically virtualization technology, by using virtualization, all severs and the software application which are required by other cloud providers are maintained by the third-

Foundation Course on Information Technology Outsourcing party people, and the cloud providers has to pay the money on monthly or annual basis. VMware Infrastructure History of virtualization The history of Virtualization has been displayed below:

Foundation Course on Information Technology Outsourcing History of Virtualization Virtualization was first developed in the 1960s to partition large, mainframe hardware for better hardwareutilization. Today, computers based on x86 architecture are faced with the same problems of rigidity andunderutilization that mainframes faced in the 1960s. VMware invented virtualization for the x86 platform in the1990s to address underutilization and other issues, overcoming many challenges in the process. Today, VMwareis the global leader in x86 virtualization, with over 300,000 customers, including 100% of the Fortune 100. In the Beginning: Mainframe Virtualization Virtualization was first implemented more than 30 years ago by IBM as a way to logically partition mainframecomputers into separate virtual machines. These partitions allowed mainframes to multitask: run multiple applications and processes at the same time. Since mainframes were expensive resources at the time, they weredesigned for partitioning as a way to fully leverage the investment The Need for x86 Virtualization Virtualization was effectively abandoned during the 1980s and 1990s when client- server applications andinexpensive x86 servers and desktops led to distributed computing. The broad adoption of Windows and theemergence of Linux as server operating systems in the 1990s established x86 servers as the industry standard. Thegrowth in x86 server and desktop deployments led to new IT infrastructure and operational challenges. Thesechallenges include • Low Infrastructure Utilization. Typical x86 server deployments achieve an average utilization of only10% to 15% of total capacity, according to International Data Corporation (IDC), a market research firm. Organizations typically run one application per server to avoid the risk of vulnerabilities in oneapplication affecting the availability of another application on the same server. • Increasing Physical Infrastructure Costs. The operational costs to support growing physical infrastructurehave steadily increased. Most computing infrastructure must remain operational at all times, resulting inpower consumption, cooling and facilities costs that do not vary with utilization levels. • Increasing IT Management Costs. As computing environments become more complex, the level of specialized education and experience required for infrastructure management personnel and the associatedcosts of such personnel have increased. Organizations spend disproportionate time and resources onmanual tasks associated with server maintenance, and thus require more personnel to complete thesetasks.

Foundation Course on Information Technology Outsourcing • Insufficient Failover and Disaster Protection. Organizations are increasingly affected by the downtime of critical server applications and inaccessibility of critical end user desktops. The threat of security attacks, natural disasters, health pandemics and terrorism has elevated the importance of business continuityplanning for both desktops and servers. • High Maintenance end-user desktops. Managing and securing enterprise desktops present numerouschallenges. Controlling a distributed desktop environment and enforcing management, access and security policies without impairing users’ ability to work effectively is complex and expensive. Numerous patchesand upgrades must be continually applied to desktop environments to eliminate security vulnerabilities. The VMware Solution: Full Virtualization of x86 Hardware In 1999, VMware introduced virtualization to x86 systems to address many of these challenges and transform x86systems into a general purpose, shared hardware infrastructure that offers full isolation, mobility and operatingsystem choice for application environments. Challenges & Obstacles to x86 Virtualization Unlike mainframes, x86 machines were not designed to support full virtualization, and VMware had to overcomeformidable challenges to create virtual machines out of x86 computers. The basic function of most CPUs, both in mainframes and in PCs, is to execute a sequence of stored instructions (ie, a software program). In x86 processors, there are 17 specific instructions that create problems whenvirtualized, causing the operating system to display a warning, terminate the application, or simply crashaltogether. As a result, these 17 instructions were a significant obstacle to the initial implementation of virtualization on x86 computers. To handle the problematic instructions in the x86 architecture, VMware developed an adaptive virtualization technique that traps these instructions as they are generated and converts them into safe instructions that can bevirtualized, while allowing all other instructions to be executed without intervention. The result is a high-performancevirtual machinethat matches the host hardware and maintains total software compatibility. VMwarepioneered this technique and is today the undisputed leader in virtualization technology Key features of Virtualization • Increased Security – The ability to control the execution of a guest program in a completely transparent manner opens new possibilities for delivering a secure, controlled execution environment. All the operations of the guest programs are

Foundation Course on Information Technology Outsourcing generally performed against the virtual machine, which then translates and applies them to the host programs. A virtual machine manager can control and filter the activity of the guest programs, thus preventing some harmful operations from being performed. Resources exposed by the host can then be hidden or simply protected from the guest. Increased security is a requirement when dealing with untrusted code. Example-1: Untrusted code can be analyzed in Cuckoo sandboxes environment. The term sandbox identifies an isolated execution environment where instructions can be filtered and blocked before being translated and executed in the real execution environment. • Managed Execution – In particular, sharing, aggregation, emulation, and isolation are the most relevant features. Virtualization Features • Sharing – Virtualization allows the creation of a separate computing environment within the same host. This basic feature is used to reduce the number of active servers and limit power consumption. • Aggregation – It is possible to share physical resources among several guests, but virtualization also allows aggregation, which is the opposite process. A group of separate hosts can be tied together and represented to guests as a single virtual host. This functionality is implemented with cluster management software, which harnesses the physical resources of a homogeneous group of machines and represents them as a single resource. • Emulation – Guest programs are executed within an environment that is controlled by the virtualization layer, which ultimately is a program. Also, a completely different environment with respect to the host can be emulated, thus

Foundation Course on Information Technology Outsourcing allowing the execution of guest programs requiring specific characteristics that are not present in the physical host. • Isolation – Virtualization allows providing guests whether they are operating systems, applications, or other entities with a completely separate environment, in which they are executed. The guest program performs its activity by interacting with an abstraction layer, which provides access to the underlying resources. The virtual machine can filter the activity of the guest and prevent harmful operations against the host. Besides these characteristics, another important capability enabled by virtualization is performance tuning. This feature is a reality at present, given the considerable advances in hardware and software supporting virtualization. It becomes easier to control the performance of the guest by finely tuning the properties of the resources exposed through the virtual environment. This capability provides a means to effectively implement a quality-of-service (QoS) infrastructure. • Portability – The concept of portability applies in different ways according to the specific type of virtualization considered. In the case of a hardware virtualization solution, the guest is packaged into a virtual image that, in most cases, can be safely moved and executed on top of different virtual machines. In the case of programming-level virtualization, as implemented by the JVM or the .NET runtime, the binary code representing application components (jars or assemblies) can run without any recompilation on any implementation of the corresponding virtual machine. Popular vendors of virualizations Virtualization Vendors

Foundation Course on Information Technology Outsourcing • VMware-The first commercial X86 virtualization product was launched in 2001 by VMware. Nowadays VMware is the virtualization market leader and it has a rich portfolio of products for both the consumer and enterprise worlds. VMware ESX is the bare-metal solution with an easy-to-use management UI that allows you to deploy full virtualized machines. • Xen-Two years later the open-source Xen project began at the University of Cambridge and it offers both full and paravirtualization. It's based on the Linux kernel. Xen has an active user base of more than 10 million users and is also used by Amazon, SoftLayer, and Rackspace. Citrix is a multinational software company founded in 1989 and it offers commercial products based on Xen. Xen server is a bare metal solution and a competitor of VMware ESX and ESXi. The Xen Center application is the Citrix tool used to create and manage Xen server installations. It is quite similar to the VMware-viclient. • KVM- KVM is a more recent product of the Linux universe that allows users to create virtual machines on top of their particular distributions. KVM supports full and paravirtualization. • Microsoft Hyper-V-Microsoft released Hyper-V a hosted and bare-metal hyper visor in 2008. An important remark regarding Hyper-V is the Microsoft license strategy. You can create unlimited Windows server power virtual machines simply by purchasing one license of the Microsoft Windows Server Data Center Edition. 7.3 Microsoft Virtualization Hyper-V is a virtualization software created by Microsoft. In this Hyper-V virtualization tutorial, we’ll look at some of the major Hyper-V virtualization concepts. In addition to covering the basics of Hyper-V virtualization and hardware virtualization technology, we’ll consider the benefits of virtualization, how virtual machines are managed, how to use Hyper-V virtualization technology, and Hyper-V considerations you should be aware of. This should provide you with a robust understanding of the nuances of Hyper-V virtualization technology.

Foundation Course on Information Technology Outsourcing Hyper-V virtualization Hyper-V is a virtualization software initially released in 2016 by Microsoft. It’s built into Windows and is widely recognized as a major competitor to VMware Fusion and Oracle VM VirtualBox. Hyper-V can be used to virtualize hardware components and operating systems. Additionally, it’s not limited to the user’s device and can be used to facilitate server virtualization. There are three versions of Hyper-V available: ▪ Hyper-V Server: a stand-alone product created for managing dedicated and virtual server instances ▪ Hyper-V for Windows 10: a product you can run on your laptop or desktop ▪ Hyper-V for Windows Server: an add-on for Windows Server Hardware virtualization is also referred to as hardware-assisted virtualization. It involves embedding virtual machine software into a server’s hardware component. This software goes by several names, but “virtual machine monitor” and “hypervisor” are the ones most commonly used. ESX Host ESX host can be defined as: • The server’s /data storage devices on which the ESX or ESXi hypervisor has been installed • It is used to create VMs (virtualization) is highly efficient, as one host device can support multiple (up to a dozen or more) VMs.

Foundation Course on Information Technology Outsourcing ESX Host ESX server is a virtualized platform, owned by VMware. ESX has two versions of servers– ESXi server and ESX server. ESX server is a tool of an enterprise level. It uses different services that handle different virtual machines and these machines are much efficient and reliable, as compared to other Server products of VMware because it runs on bare metal. This means that the software of the ESX server can be installed directly without additional operating system. VMkernel (a micro kernel for saving resources) controls the basic system of ESX server. This diminishes the need for running OS beneath the VM. After the setup, resources get divided into virtual hardware, for virtual machines usage. VMkernel is responsible for running the programs smoothly including the virtual machines, agents and management applications. It can also control hardware, and manage the resources. The processes running on VMkernel, are • Virtual machine monitor – This process is responsible for ensuring the providence of the execution environment of a VM. A process called VMX is also initiated by it. Each VM has its own VMX and VMM processes. • Direct Console User Interface (DCUI) – This is an interface for management and configuration. DCUI is accessible through the server console. DCUI is used for basic initial level configuration. • CIM (Common Information Model) system – The Common Information Model is an interface enabling control of the hardware management from the remote applications by APIs.

Foundation Course on Information Technology Outsourcing • Agents – Agents control the VMware infrastructure from remote applications. ESX server has the capacity to memorize which is the best feature so far. This means that the memory of the VM can be greater than the server’s memory. This is the case of memory’s better utilization. The process is controlled by the service console.ESX server architecture is designed to increase its reliability, management, and security. The architecture can be integrated into a virtually optimized server. It means: • Smooth deployment. • Hassle free configuration. • Quick installation. ESX server communicates by Host Agents by using API or VI API and their information can be gathered vCenter vcenter vCenter Server is an application that enables you to manage your vSphere infrastructure from a centralized location. It acts as a central administration point for ESXi hosts and their respective virtual machines. vCenter Server can be installed on a supported version of Windows or you can use a preconfigured Linux version known as vCenter Server Appliance. vCenter Server is required for some advanced vSphere features, such as vSphere High Availability, vSphere Fault Tolerance, vSphere Distributed Resource Scheduler (DRS), VMware vSphere vMotion, and VMware vSphere Storage vMotion.A single vCenter Server instance can support a maximum

Foundation Course on Information Technology Outsourcing of 1,000 hosts, 10,000 powered-on virtual machines and 15,000 registered virtual machines. vCenter Server is an application that enables you to manage your vSphere infrastructure from a centralized location. It acts as a central administration point for ESXi hosts and their respective virtual machines. vCenter Server can be installed on a supported version of Windows or you can use a preconfigured Linux version known as vCenter Server Appliance. vCenter Server is required for some advanced vSphere features, such as vSphere High Availability, vSphere Fault Tolerance, vSphere Distributed Resource Scheduler (DRS), VMware vSphere vMotion, and VMware vSphere Storage vMotion.A single vCenter Server instance can support a maximum of 1,000 hosts, 10,000 powered-on virtual machines and 15,000 registered virtual machines. A vCenter Server instance consist of the following components: • vSphere Client and vSphere Web Client – both tools can be used to manage your vCenter Server. vSphere Web Client is the recommended way to manage an ESXi host when the host is managed by vCenter Server. • vCenter Server database – stores the inventory items, security roles, resource pools, performance data, and other information. Oracle and Microsoft SQL Server are supported databases for vCenter Server.vCenter Single Sign-On (SSO) – allows authentication against multiple user repositories, such as Active Directory or Open LDAP. • Managed hosts – ESXi hosts and their respective virtual machines. Here is a picture of a vSphere environment managed through vCenter Server: Vcentre Server

Foundation Course on Information Technology Outsourcing 7.4 Summary • Virtualization is the process of running a virtual instance of a computer system in a layer abstracted from the actual hardware • Virualization purpose is to run applications normally requiring multiple units of hardware • Virtualization relies on software to simulate hardware functionality and create a virtual computer system. • virtualization popular vendors are vmWare, Misrosoft Hyper-V.KVM, Xen. 7.5 Learning Activity Install VirtualBox Guest Additions, this lab will test your ability to install, configure, and set up VirtualBox on your laptop, create a VM, and install a guest operating system 7.6 Glossary • Child partition - A child partition is a logical hard drive division in the Microsoft Hyper-V environment that runs an isolated operating system. • Virtual Server: A virtual server typically runs one server-based application. • Virtual Desktop: A VM that is running a desktop OS such as Windows 7 or Red Hat Enterprise Desktop. • Virtual Network: A network provided by virtual switches 7.7 References • https://opensource.com/resources/virtualization • https://www.softwaretestinghelp.com/virtualization-software/ • https://www.vmware.com/in/products/esxi-and-esx.html • https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/produ cts/vCenter/vmware-vcenter-server-datasheet.pdf