From Kerrighed

Contents 1 Virtual Images 1.1 Requirements 1.1.1 Hardware 1.1.2 Software 1.2 Quick Install 1.3 Login 1.4 Kerrighed usage

Virtual Images

Virtual images are the fastest way to test Kerrighed. The first virtual machine boot a system with the Kerrighed kernel, share its root filesystem through NFS and setup a TFTP/PXE boot server. Then, you can boot up to 16 other diskless virtual machines through PXE and they will join the cluster.

Requirements

Hardware

• KVM kernel module provides accelerated virtualization and processors supporting it. For an official list of supported Intel processors, have a look at this page. For AMD processors, you may refer to this wikipedia page.
• Each virtual machine is pre-configured to use 512MB of RAM. The light version (without graphical interface) can run with less memory.

Software

• We use libvirt with qemu/kvm to run the images. On a Debian system, you can install it with:

apt-get install libvirt-bin qemu-kvm

• PXE ROM is included in Qemu in recent versions. Depending on your distribution, it can be distributed in a separate package. On Ubuntu, for instance:

apt-get install kvm-pxe

• libvirt project provides a nice gui to manage local or even distant virtual machines.

apt-get install virt-manager

• As their are quite big, we provides only torrent files to get images. Don't forget to share a bit of your bandwidth once downloaded, if possible.

apt-get install bittorrent

Quick Install

If you never run libvirt on your system before, please ensure you have read the requirements chapter.

• Download the master image, for instance the light one:

btdownloadcurses http://www.freetorrent.fr/download.php?id=2dec616bbc1cf7d48cb71de44f169d4cbd246a99&f=Kerrighed%20kvm%20image.torrent

• Download the definitions:

wget http://download.kerlabs.com/kerrighed/libvirt-definitions.tar.bz2

• Extract the image:

sudo sh -c 'bzcat -c krg0_light.img.bz2 > /var/lib/libvirt/images/krg0.img'

• • The virtual image is a 8GB file. However, the file is sparse so that you can save a lot of space extracting it with the following command:

sudo sh -c 'bzcat -c krg0_light.img.bz2 | cp --sparse=always /dev/stdin /var/lib/libvirt/images/krg0.img'

• Extract the definitions:

tar jxf libvirt-definitions.tar.bz2

• Create the network from the definition. It will setup a bridge with the address '192.168.122.254' and a DHCP server which will give the first node the address '192.168.122.1'.

sudo virsh net-create default.xml

• Create the 4 virtual machines from the 4 definition files:

sudo virsh define krg0.xml
sudo virsh define krg1.xml
sudo virsh define krg2.xml
sudo virsh define krg3.xml

• As they have no disk and boot from the network, all nodes except the first one can be duplicated just by changing their name and mac address.
• Start the first node:

sudo virsh start krg0

• Once started, you can boot other virtual machines.

sudo virsh start krg1
...

Please have a look at libvirt documentation for advanced usage of 'libvirt'. You may also want to use 'virt-manager' to start/stop the machines and other fancy stuff through a gui.

Login

You can access the machines through 'ssh' and with following login:password pairs:

root: kerrighed
kerrighed: kerrighed

You can access the root container of each machine through ssh on port 2222.

Kerrighed usage

Have a look at 'krgadm(1)' manpage to see how to see cluster machines and add them to the cluster.