Scroll to navigation

fai-diskimage(8) System Manager's Manual fai-diskimage(8)


fai-diskimage - create a disk image for booting a VM


fai-diskimage imagename


fai-diskimage creates a disk image that can be used with Qemu/KVM, VirtualBox, VMware, Xen, Android device or by your cloud infrastructure. It runs the Fully Automatic Installation using a list of FAI classes. In the end you have a bootable disk image. Following formats are supported: .raw.xz, .raw.zst, .qcow2, .vdi, .vhdx, .vmdk, .simg.


Define list of FAI classes
Print help
This option will be passed to the fai call. It then executes the scripts in class/[0-9]* for defining classes.
Set size of raw image (suffixes k M G T are supported)
Location of the config space. If location starts with /, the prefix file:// will be added. See fai.conf(5) for all supported protocols. Default is /srv/fai/config.
Set hostname to name
Be verbose


First, setup the configuration space. You will get an initial configuration including several examples.

# fai-mk-configspace

You can now build your fist disk image.

# fai-diskimage -vu cloud3 -S2G -c$cl cloud.raw

Creates a Debian system with a small set of software packages without graphical desktop. The disk image cloud.raw will be of size 2 GB and the host is called cloud3.

# fai-diskimage -vNu ubuntu -S7G -c$cl ubuntu.qcow2

Creates a disk image of size 7GB called ubuntu.qcow2 for a Ubuntu 16.04 desktop.


fai-diskimage will use zerofree if it's available on the host for getting better compression of the raw images.

Before creating an image, make sure you have the configuration space available. Create the config space for FAI by using the examples from the fai-doc package.

# fai-mk-configspace

fai-diskimage is not limited to creating images for virtual machines. The raw images can also be copied (via dd) onto a real disk for booting bare metal hosts.

You can start fai-diskimage in a clean shell environment by calling:

# env -i /usr/sbin/fai-diskimage -vNu cloudhost -S5G -cBULLSEYE64,GCE disk.raw

You can also build cross-architecture disk images using fai-disimage. See the chapter "Building cross-architecture disk images" in the FAI guide for details.


This program is part of FAI (Fully Automatic Installation). See the FAI manual for more information on how to use fai-monitor. The FAI homepage is


Thomas Lange <>

September 2018 FAI 5.7