System image: Clone & deploy
Mayank Sharma shows you how to image and rollout several computers.
Managing a network of computers is an involved process. Before you can tackle the problem of actively monitoring the machines, you have to install an operating system on each one of them. This is a time-consuming task even for a small network with about 10 computers. Computer cloning involves setting up the operating system, drivers, software and data on one computer, then automatically replicating the same setup on other computers. This technique, known as ghosting or imaging, is used by system administrators for rolling out multiple identical machines over the network without much effort. Fog, which we’ll use here, is one of the most popular open source cloning systems.
To use Fog you, first, need to setup an imaging server. The project officially supports several Ubuntu, Fedora, Debian, and CentOS releases, but it’s known to work on other distributions (distros) as well. Before installing Fog make sure the server has a static IP address, which you can ensure from your router’s admin page. For this tutorial we’ll assume our Fog server is at 192.168.3.51. Also ensure that all the machines in your network are configured to boot from the network card. Finally, make sure you disable any existing DHCP servers on the network as we’ll set up the Fog server as a DHCP server and dole out addresses to all the computers on the network.
Once you have your network set up, head to the machine that’ll be your deployment server and download the latest stable Fog release ( http://sourceforge.net/projects/ freeghost/files/FOG). Then fire up a terminal and extract the downloaded tarball with tar xvf Fog_1.2.0.tar.gz -C /opt then change into the bin directory under the extracted tarball, and fire up the installation script with: sudo ./installFog.sh
The installation script will prompt you for several bits of information such as the version of Linux you’re running it on, the type of installation, the IP address of the server, the router and the DNS server and whether you’d like to setup the Fog server’s own DHCP server. In most cases, it’s best to go with the default options suggested by the installer, but make sure you enter the correct IP addresses for the server.
The script will install various required components. When it’s done it’ll display a URL for Fog’s dashboard (such as 192.168.3.51/fog/management). Open the link in your web browser and log in with the default credentials ( fog:password). On initial launch you’ll have to load the default settings into the server’s database by clicking on the button on the page. The first order of business when you are at the proper admin dashboard is to create a new user. To do this head to User Management > Create New User.
Creating a base image
Now that our imaging server is set up, we’ll use it to image a computer. Once a computer has been imaged we can then deploy that image to other computers with a single click.
To begin the process, fire up a browser on the imaging server and head to Fog’s dashboard and log in with the default credentials. Then head to Image Management > Create New Image. Use the fields in the form to describe the image, eg, let’s assume we are creating an image of Fedora Workstation 22 installation that we’ll then install on all our computers in the Science Lab. So we can name the image ‘Fedora for Science Lab’.
Next, use the Operating System pull-down menu to specify the operating system of this image, such as Linux. Finally, select the correct disk layout scheme from the Image Type pull-down menu. Our Fedora installation is on a single disk with multiple partition so we’ll select the second option. Now assuming you’ve already installed Fedora on one of the