Virtualization.pdf
- 1. Virtualization fundamental idea behind a virtual machine. abstract the hardware of a single computer. CPU, memory, disk drives, network interface cards. “Virtual machine implementations involve several components.” Virtual machine manager (VMM) or hypervisor creates and runs virtual machines by providing interface that is identical to the host (Except in the case of PARAVIRTUALIZATION) Guest process provided with virtual copy of the host Implementation of VMMS Type 0 hypervisors Hardware-based solutions that provide support for virtual machine creation and management via firmware (Including VMware ESX, Joyent SmartOS, and Citrix XenServer) Type 1 hypervisors Operating-system-like software built to provide virtualization (Including VMware ESX, Joyent SmartOS, and Citrix XenServer) Type 1 hypervisor operating systems that provide standard functions as well as VMM functions Microsoft Windows Server with HyperV and RedHat Linux with KVM Type 2 hypervisors Applications that run on standard operating systems but provide VMM features to guest operating systems VMware Workstation and Fusion, Parallels Desktop, and Oracle VirtualBox Paravirtualization guest operating system is modified to work in cooperation with the VMM to optimize performance Programming-environment virtualization VMMs do not virtualize real hardware but instead create an optimized virtual system(Used by Oracle Java and Microsoft.Net) Emulators Allow applications written for one hardware environment hardware environment, such as a different type of CPU. Application containment Not virtualization at all but rather provides virtualization like features by segregating applications from the operating system, making them more secure, manageable (Including Oracle Solaris Zones, BSD Jails, and IBM AIX WPARs) Benefits and Features the host system is protected from the virtual machines, just as the virtual machines are protected from each other virus inside a guest operating system might damage that operating system but is unlikely to affect the host or the other guests implementations are the ability to freeze, or suspend, a running virtual machine. VMMs go one step further and allow copies and snapshots to be made of the guest The guest can then resume where it was, as if on its original machine, creating a clone. virtual machine system is a perfect vehicle for operating-system research and development. multiple operating systems can run concurrently on the developer’s workstation multiple versions of a program can run, each in its own isolated operating system, within one system. One of the tools that make this possible is templating, in which one standard virtual machine image, including an installed and configured guest operating system and applications, is saved and used as a source for multiple running VMs VMMs include a live migration feature that moves a running guest from one physical server to another without
- 2. interrupting its operation or active network connections