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DEBIRF(1) User Commands DEBIRF(1)


debirf - build an initrd to boot a full Debian system entirely from RAM


debirf <subcommand> [options] [args]


debirf (DEBian on Initial Ram Filesystem) is a set of tools designed to create and prepare a kernel and initial ram filesystem that can run a full-blown Debian environment entirely from RAM.

debirf has various subcommands (see SUBCOMMANDS) which act on a specified debirf profile (see PROFILES).

The debirf system is outlined at:


Make a stock debirf rescue image using the default settings:

$ tar xzf /usr/share/doc/debirf/example-profiles/rescue.tgz
$ debirf make rescue

Make a debirf rescue image, specifying the mirror and a local HTTP proxy:

$ tar xzf /usr/share/doc/debirf/example-profiles/rescue.tgz
$ DEBIRF_MIRROR= http_proxy= debirf make rescue


debirf takes various subcommands:

Create a debirf system based on profile PROFILE. This will create the root for the profile, run all modules on the root, and then generate the kernel image (see KERNEL) and debirf initramfs. This subcommand takes various options (see OPTIONS).
Chroot into root of profile PROFILE, with full profile environment.
Create a bootable CD-ROM image from the kernel and initramfs in PROFILE. This requires a bootloader to be available. If grub-mkrescue (in the grub-common package on debian) is available, it will be used. Otherwise, isolinux is used if it is available. You may use the DEBIRF_ISO_BOOTLOADER environment variable to specify a preference manually (see below).
Output a brief usage summary.

OPTIONS (for make subcommand only)

check variables before make
create new root, even if old one exists
debootstrap on top of old root if it exists
skip debootstrap step altogether if old root exists
use real chroot to build instead of fakechroot (requires superuser privileges or CAP_SYS_CHROOT)
skip superuser warning
remake initramfs from existing root (skip debootstrap and module stages)
install KERNEL .deb, instead of default kernel


A debirf profile is a directory containing a debirf.conf config file and a modules sub-directory (see MODULES).


If the profile directory includes a 'packages' file, it is interpreted as a list of packages to include/exclude during the debootstrap stage. Packages should be specified one per line, with a '+' prefix to indicate inclusion during debootstrap, or a '-' prefix to indicate exclusion.


Modules are used to configure the debirf system, and can be used to extend the capabilities of debirf. Modules are bash shell scripts that are executed in alpha-numeric order by run-parts in a chroot in the debirf root during the module stage of the debirf build. The module stage is right after the debirf debootstrap stage, and right before the initramfs archive is created. All shell variables beginning with "DEBIRF_", including those defined in the debirf.conf file, are available to the modules.

Modules may specify packages to be included/excluded during the debootstrap stage with special '#DEBIRF_PACKAGE>' comments anywhere in the module. Lines beginning with '#DEBIRF_PACKAGE>+' specify packages to include, and lines beginning with '#DEBIRF_PACKAGE>-' indicate packages to exclude. Only one package should be specified per comment line (no spaces). So for instance, the lines:

would include the packages emacs and ed, and would exclude the package nano.

NOTE: Some modules are more important to the proper functioning of debirf than others, and the ordering of modules is important. Some modules may depend on certain other modules having already been, or not yet been, run. For instance, the module that cleans the debirf apt cache ("z1_clean_root") should be the last module run at the end of the module stage.


The debirf "install-kernel" module will try to pick the most up-to-date kernel for the suite you are installing (versions 2.6 only), with the arch determined by the kernel running on the host build system.


A set of pre-defined bash shell functions are available to the modules to fasciliate configuring the debirf system:

Execute <command> within debirf root (DEBIRF_ROOT) with chroot.
Output a message to standard out during the build process.
Cause debirf script to fail with <exit-code>, and <message> to stderr.
Write one line of sh code to the file on the debirf root.
Write one line of comment to the file on the debirf root.


The following environment variables are used by debirf:

debirf label (default: debirf)
where to build the debirf (default: ./)
architecture to build (default is the architecture of the build machine)
suite to build from (default determined from lsb_release, otherwise "sid")
distro for suite (default determined from lsb_release, otherwise "debian")
mirror to pull suite (default determined by DEBIRF_DISTRO)
keyring to verify debootstrap (default determined by DEBIRF_DISTRO)
the flavor of kernel debirf should install. Supply everything from a typical debian package name after the version number. e.g. 486, vserver-686-bigmem, openvz-amd64. (default chosen based on currently-running kernel)
whether to use "grub" or "isolinux" as the El Torito bootloader for debirf makeiso. if not specified, "grub" is the default.


Debirf profile configuration file. Contains values for the various debirf environment variables (see ENVIRONMENT). Variables specified in the debirf.conf override those specified on the command line.
File that stores various information about the debirf build. This is a bash-sourceable file.


Written by Jameson Rollins and Daniel Kahn Gillmor.


Debirf does not work as a non-privileged user across different versions of libc. In particular, this means that you probably won't be able to build an image from a different version of the operating system than you're using without building as root. (see

Please report bugs in debirf via the debian BTS:


Copyright © 2007-2011 Jameson Rollins and Daniel Kahn Gillmor
This is free software. You may redistribute copies of it under the terms of the GNU General Public License <>. There is NO WARRANTY, to the extent permitted by law.


/usr/share/doc/debirf/README, debootstrap(8), fakechroot(1)

Dec 2011 debirf 0.32