Ubuntu Manpage: debootstick - Generate a bootable image from a Debian-based chroot environment

NAME

       debootstick - Generate a bootable image from a Debian-based chroot environment

SYNOPSIS

       debootstick [options] SOURCE DEST

DESCRIPTION

       debootstick generates a bootable image (at DEST) from a Debian-based chroot environment (at SOURCE).

       SOURCE  must  be a directory containing a standard Debian-based chroot environment (such as one generated
       with debootstrap(8)).  The output image generated at DEST should then be copied to a USB stick or disk.

       The embedded system is:
       - ready to be used (no installation step)
       - viable in the long-term, fully upgradable (kernel, bootloader included)
       - compatible with BIOS and UEFI systems

       debootstick can also generate installer media. See option --system-type below.

OPTIONS

debootstick follows the usual GNU command line syntax, with long options starting with two dashes (`-').
A summary of options is included below.

-h, --help
Show summary of options.

-v, --version
Show version of program.

--help-os-support
Describe which chroot environments are supported.

--system-type [live|installer]
Specify which kind of system is targeted. The default is live. When booting a system where
installer was selected, the system will try to migrate to a larger device on first startup. If
live was selected, or if no such option was specified, no migration will occur. See section
INSTALLER MEDIA below.

--kernel-package PACKAGE_NAME
Specify the kernel that should be installed. Without this option, debootstick will install a
common one (depending on the embedded distribution).

--config-hostname HOSTNAME
Specify the hostname the embedded system will have.

--config-kernel-bootargs BOOTARGS
Specify boot arguments to be added to the kernel. (You may specify several arguments, e.g.
--config-kernel-bootargs "console=ttyS0 acpi=off".)

--config-root-password-ask
Prompt for the root password of the embedded system and set it accordingly.

--config-root-password-none
Remove the root password of the embedded system (root login will not prompt any password).

--config-root-password-first-boot
Ask for the root password when the system will be booted for the first time.

--config-grub-on-serial-line
Update grub configuration to show boot menu on serial line.

EXAMPLES

       The most common workflow is the following.

       1- Generate a chroot environment:
       debootstrap --variant=minbase jessie /tmp/jessie_tree

       2- (Optionally) customize it:
       chroot /tmp/jessie_tree; [...]; exit

       3- Generate the bootable image:
       debootstick --config-root-password-ask /tmp/jessie_tree /tmp/img.dd
       Enter root password:
       Enter root password again:
       OK
       [...]

       4- Test it with kvm.
       cp /tmp/img.dd /tmp/img.dd-test    # let's work on a copy, our test is destructive
       truncate -s 2G /tmp/img.dd-test    # simulate a copy on a 2G-large USB stick
       kvm -hda /tmp/img.dd-test          # the test itself (BIOS mode)

       5- Copy the boot image to a USB stick or disk.
       dd bs=10M if=/tmp/img.dd of=/dev/your-device

       The USB device may now be booted on any BIOS or UEFI system.

CPU ARCHITECTURES

       debootstick expects a chroot environment built for amd64 or i386 systems.  Of course, the resulting image
       will reflect this initial architecture, and thus it should be booted on a compatible system.
       debootstick also needs that the host system is able to execute binaries in the  chroot  environment.  For
       example, trying to run it with an amd64 chroot environment on an i386 host will fail.
       debootstick will check this kind of things on startup.

INSTALLER MEDIA

       When first booting a system built with the --system-type installer option, it will look for a larger disk
       and  move  to  that  disk.   This  operation  does  not require a reboot. Once done, the system will just
       continue its bootup procedure (and the initial device can be removed).
       CAUTION: Any data on the target disk will be lost.
       Also note that the system is moved, not copied. Thus the initial device cannot be used anymore after  the
       migration, unless you copy an image again, of course.

NOTES

       It  is  also  possible  to test the UEFI boot with kvm, if you have the ovmf package installed, by adding
       -bios /path/to/OVMF.fd to the kvm command line.

       Many Live distributions propose a highly compressed system based on a squashfs image.  They handle writes
       using an overlay based on a filesystem union.  While this allows the system  to  remain  compact  in  the
       first times, this also has disavantages:
       -  Some important files remain read-only and cannot be upgraded (that is the case of the linux kernel and
       the bootloader) which quickly leads to security issues or upgrade problems.
       - Storing modified files in an overlay and never releasing the room needed for the original  versions  in
       the squashfs image is counter-productive in the long term.
       One  of  the  objectives behind debootstick was to provide a viable long-term live system, therefore this
       kind of setup has been discarded.

AUTHOR

       Etienne Duble (etienne.duble@imag.fr)