Book Image

Oracle VM Manager 2.1.2

By : Tarry Singh
Book Image

Oracle VM Manager 2.1.2

By: Tarry Singh

Overview of this book

Virtualization is taking the technology world by storm and dramatically helping organizations save money. Oracle VM is free and forked from the open source Xen hypervisor, which brings down your upfront costs for an agile data center. The robust capabilities and easy-to-use web interface of Oracle VM Manager helps administrators manage their Internal Data Center from anywhere in the world, helping us come closer to ubiquitous computing. This practical book will give you hands-on experience on how to manage your Virtual Machines using Oracle VM Manager. Equipped with step-by-step installation and management information you will not only learn to manage your Virtual Data Center but also will include this guide among the books you consider most essential. This book will take you into the various methods of importing Virtual Machines. You will learn to import VMs through HTTP/FTP, Repository servers, and even import other VM formats such as VMware VMs. You will also learn about the Xen utilities such as xm, xentop, and virsh. You will learn to manage your VMs through the simple and intuitive web interface of Oracle VM Manager. No matter how compact it may seem, this book covers all the essentials while keeping your learning experience to the point. The book has been deliberately written in a conversational manner so that you feel at home while learning Oracle VM Manager.
Table of Contents (15 chapters)
Oracle VM Manager 2.1.2
About the Author
About the Reviewer

Oracle VM Server

The Oracle VM Server uses the Xen hypervisor technology and Oracle VM Agent. It includes a Linux kernel with support for devices, file systems, and so on. The Linux kernel runs as a dom0 and manages other DomU or VMs, called domains in Xen, the para-virtualization terminology. So essentially dom0 is the first guest booted and typically represents the physical machine by functioning as the supervisor module. Here the DomU could be a Linux, Solaris, or a Windows VM as we can see in the following image.

Xen hypervisor, Domains, and Virtual Machines

Oracle VM Server is designed so that the only entity that has full control of the system is the hypervisor or so called VMM. It is thin and is constructed using extremely well written code which basically handles your resources and interrupts.

In Xen terminology, we will see Domains, Guests, and VMs are often used interchangeably but they do have their differences. Simply said—Domain, with its virtual four-cores allows a VM to run on it, whereas a Guest is an operating system that runs within a Domain in para-virtualized or hardware virtualized mode (as explained earlier in the modes). A VM or to make it even more stylish, a Virtual Appliance is an operating system with the associated application running inside it.

VMs within an Oracle VM platform that run in para-virtualized modes need the necessary kernel modification and run at near-native speeds. Should the VMs run on hardware-assist virtualization, they run completely unmodified. Such hardware-assisted VMs are carefully monitored for instruction set changes and manipulations. The good part is that Operating Systems such as Microsoft Windows run fine as hardware-assisted VMs.

A lot of work, such as hardware detection in an Oracle VM Server, is performed by the Management domain also referred to as dom0. The VMs are often referred to as DomU. The dom0 is a complete kernel with a vast array of drivers and provides extensive support for file systems, volume management, and much more.

Looking quickly at the big picture, we get an idea of the basic Oracle Cloud Farm that could be built when the consumer starts using Oracle's VM Server and Oracle VM Manager on a large scale.

The following diagram is a high level view of how a typical Oracle Cloud farm can be built with Oracle VM Servers placed in various data centers and Oracle VM Manager managing the farms.