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- (Optionaly) 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)