If you are looking at this file at http://libguestfs.org/download/builder ------------------------------------------------------------------------- This directory is used by the libguestfs 'virt-builder' to store the clean, signed OS templates used for building new virtual machines. The index file is the default source URL and links to the other OS templates. It has the canonical URL: http://libguestfs.org/download/builder/index.asc If you are looking at this file in the git repository ----------------------------------------------------- libguestfs.git/builder/templates/ contains the program used to generate the template files, the source for the index, kickstart files and more. When you use the ./run script to run virt-builder without installing, the ./run script sets $VIRT_BUILDER_SOURCE to point to this directory. If you actually want to use this configuration for anything except simple testing, you will have to download one or more OS templates from the libguestfs website and put them into this directory. ie: ./run virt-builder fedora-20 will fail unless you have downloaded fedora-20.xz here. Fedora guests ------------- The general plan for using kickstart and virt-install is outlined by Kashyap here: http://kashyapc.wordpress.com/2011/08/18/unattended-guest-install-with-a-local-kickstart/ If you want to reproduce the builds then the kickstart files are located in fedora-.ks and the virt-install + other commands are in fedora-.sh.