Chapter 2. Installing SystemImager

2.1. How Does it Work?

SystemImager uses a centralized server, called image server that retrieves a golden client's entire system image and deploys it to any number of different client systems. A golden client is a system you have customized to work exactly the way you want. You can re-compile the kernel, install custom software, and do any configuration file tweaking you like. The si_getimage(8) command pulls the golden image to the image server for deployment to other systems.

Once you have deployed the initial image to your client systems, you can update/upgrade the client systems by syncing them to an updated image on the image server. Only the modified parts of files are pulled to the client for a fast, efficient, and accurate mass update/upgrade.

Note

Tools other than SystemImager are available for doing automatic installations, such as Red Hat's Kickstart, which installs systems based on a list of pre-defined packages or debootstrap, used to create a Debian base system from scratch. However, such package-based installs can be very limiting because they don't have an automated way to deal with non-packaged files. If you re-compile your kernel, add a piece of non-packaged software, or modify certain configuration files, package-based installation methods usually require you to do some sort of scripting or programming to deal with these "special cases."