Virtualisation(xen hypervisor and xen guest installation)

[venka2kcbe]

Virtualisation:

Virtualisation refers to a scheme in which the hardware is abstracted by a software layer allowing us to run multiple OS in a single machine. The concept of virtualisation can be considered as an extension of running multiple process on a single machine where OS is the single point of contact.

Types of Virtualisation:

Full Virtualisation and Para-Virtualisation

Full Virtualisation : The virtualisation software provides a complete emulation of the underlying hardware where the guest os thinks as it is running on its own hardware.Eg: Vmware workstation,Virtual PC,QEMU

Para Virtualisation : The virtualisation provides an emulation of the hardware which is completely identical with the original hardware.Eg:Xen,Vmware ESX

Xen is a para-virtualization concept used in Linux OS as a virtualisation software.

System Requirements: The latest updated Linux OS with updated kernel is needed.The following OS supports Xen Redhat EL 5,Fedora Core 12,CentOS 5,Debian based Linux OS

Xen Pre-requites:

1. Centos 5 was installed and yum installation & configuration inorder to update the latest kernel.

2. Install Apache,NFS,FTP,Bridge-utils,libvirtd,Gcc, virt-manager

Installing Xen hypervisor(Host kernel):

1. To install xen --- yum install kernel-xen xen

2. Use mkinitrd command to have the image of the latest kernel --- mkinitrd /boot/initrd.2.6.img 2.6.167 (as per the latest kernel installed under the path /lib/modules/)

3. Edit the grub.conf inorder to update latest kernel and initrd images --- vi /etc/grub.conf

4. Boot the xen with the latest kernel

5. After booting the OS with the xen kernel try these commands -- xm list, xm info, virt-install, virt-manager

6. Virt-Manager is a gui tool for installaing the xen guest

7. Install Apache or NFS or FTP for the proceeding of guest OS

Installing the Xen guest:

1. Use virtmanger & to start the virt-manager panel

2. Click the new host option to start the guest host installation

3. The xen guest can be installed via FTP,NFS,HTTP options

4. Select the appropriate installation method and install the guest os.

5. After the installation is over , start the guest using the xm create <img-name-used> -c