Ubuntu Manpage: bilibop - run Debian GNU/Linux from an external media

NAME

       bilibop - run Debian GNU/Linux from an external media

DESCRIPTION

A lot of GNU/Linux distributions - at least the most popular of them - provide freely
downloadable .iso or .img disk images that can be copied on a USB memory stick (sometimes
with just cat(1) or dd(1), sometimes in a more complicated way) and immediately usable 'as
is'.

But such operating systems are not designed to be modified; they are read-only, and even
when they provide a 'persistent' feature, it is limited. Additionally, they are currently
unmaintainable, in the sense that rebuild the complete image of the root filesystem is the
only way to update the system or modify its settings in depth. This is often a hard or
heavy task that cannot be done from the system itself: this needs a dedicated work space,
outside of the running system, and this often needs another operating system to replace
the disk image by the new one; and some of these tasks can be done only by experienced
users. Others have to wait for the next release, if it comes a day.

Bilibop stands for 'Bilibop Is Live Install Boot On Pendrive'. This recursive acronym is
now obsolete, but the name has been kept. The bilibop project is born as an alternative to
the LiveUSB systems.

By performing a standard installation of Debian directly on a removable media — currently
a USB key or an external HDD — it is possible to use it as a LiveUSB system, with the big
difference that it behaves like any installed Debian OS: it can be maintained, modified,
updated, or even broken by the root user at any time. In fact, without specific settings,
it can be broken by an unprivileged user at any time; but this is also the case of LiveUSB
systems.

So, bilibop is a collection of scripts using or used by other programs
(initramfs-tools(7), udev(7), or GRUB2) to help admins to maintain a Debian GNU/Linux
operating system installed on a removable and writable media, even if some of these
scripts may also be used in other contexts. One of its main goals is to fix security
issues or harden standard rules and policies, to make the system more robust in this
particular situation. Instead of yet another new, living fast and dying young, Debian
based distribution, bilibop has been designed as a set of few debian packages.
bilibop-lockfs may also be installed on a laptop or on a public computer as an alternative
to fsprotect or overlayroot, and bilibop-udev (or bilibop-rules) should also be installed
on a LiveUSB.

BILIBOP PACKAGES

       bilibop
         This is a meta package, depending on several other binary packages from the same bilibop
         source package.

       bilibop-common
         It  mainly  provides  shell  functions  and  documentation.  See  README.Debian  in  the
         documentation  of  the  package for details about these functions.  It also includes the
         drivemap(1) command.

       bilibop-rules
         This package provides udev rules and helper scripts. Its main  purpose  is  to  fix  the
         external  drive  hosting  the  running  system,  and all its partitions, as owned by the
         'disk' group instead of 'floppy', as done by the common udev rules applied to  removable
         media. This is a workaround of the bug #645466.  The udev rules provided by this package
         work even when the root filesystem is on a LUKS device, a LVM  Logical  Volume,  a  loop
         device  or  is  an  aufs(5)  or  overlay  mountpoint.   bilibop-rules  also includes the
         lsbilibop(8) command, and  some  helper  scripts  in  /usr/share/bilibop,  that  can  be
         executed  manually  or  with 'dpkg-reconfigure bilibop-rules'.  See README.Debian in the
         documentation of the package for details.

       bilibop-udev
         This package is a kind of subset of  bilibop-rules,  and  is  more  suited  for  LiveUSB
         systems.  It  just  makes  that  the  drive  hosting  the  running  system,  and all its
         partitions, belong to the 'disk' group instead of 'floppy'.  Its udev rules also  create
         a  symlink  (/dev/bilibop)  pointing  to  the  drive  name.  See  README.Debian  in  the
         documentation of the package for details.

       bilibop-lockfs
         By using an initramfs script and a mount(8) helper script, filesystems  are  mounted  as
         readonly  branches  of  a union filesystem (either aufs(5) or overlay) the corresponding
         writable branches being on temporary filesystems.  Additionally, block devices  are  set
         readonly  too, avoiding low-level write access on them, even by root. All this makes the
         operating  system  unbreakable,  unless  with  a  hammer.  See  README.Debian   in   the
         documentation of the package for details.

INSTALLATION

Debian can be installed on a removable drive as it is on an internal one, except:

• It is highly recommended to install a full encrypted system. Otherwise, what can happen
if the USB stick or the external HDD has been lost or forgotten somewhere, or even
thieft ? Unfortunately (but there are evident security reasons), this can not be fully
preseeded.

• Due to write-cycles limits on flash memory, it is not recommended to use a swap area on
them: this can dramatically decrease the lifetime of the drive.

• Even if the amd64 is now the most common architecture on modern Personal Computers,
installation of a x86 system will make it more versatile and work both on amd64 and i386
architectures (and even on ia32, but this needs at least a specific partition scheme).

• Take care, near the end of the installation, that the bootloader will be installed on
the MBR of the drive where the system has been freshly installed: choosing the default
'install on MBR' will install it on the Master Boot Record of the first disk !

• Taking previous recommendations into account, choose 'Expert Install' or 'Expert
Graphical Install' in the installer boot menu. if you have to install Debian on several
devices, don't perform an automated installation via the 'Auto Install' option in the
installer boot menu. If you really need to automate this process to win time, use a
preseed file instead.

SETTINGS AND CONFIGURATION

       The main advantage of a standard installation over a Live system is that the installed one
       can exactly answer your needs: if the needs change, the system can be easily modified.  It
       can be installed and configured to be used as/for:

       • daily usage (this is my case)
       • router and/or firewall for a LAN
       • ftp and/or http server (this is my case)
       • forensics and rescue system (this is may case)
       • embedded Debian repository (this is my case)
       • testing system
       • educational purposes
       • others

       Because an operating system running from an external device is generally used on different
       computers, with potentially different keyboards, architectures, monitors, and  so  on,  it
       could  need  some  special settings to be as versatile as possible. Maybe the field is too
       large to be covered into a single manual  page:  see  /usr/share/doc/bilibop-common/misc/*
       for some tips and tricks, details and suggestions about possible settings.

FILES

       /usr/share/bilibop-common/README.Debian
       /usr/share/bilibop-common/examples/bilibop.conf
       /usr/share/bilibop-common/misc/*
       /usr/share/bilibop-lockfs/README.Debian
       /usr/share/bilibop-lockfs/examples/bilibop.conf
       /usr/share/bilibop-rules/README.Debian
       /usr/share/bilibop-rules/examples/bilibop.conf

AUTHOR

       This manual page has been written by Bilibop Project <quidame@poivron.org>.