Provided by: live-boot-doc_3.0~a24-1ubuntu1_all bug


       live-boot - System Boot Scripts


       live-boot  contains  the  scripts  that  configure a Debian Live system
       during the boot process (early userspace).

       live-boot is a  hook  for  the  initramfs-tools,  used  to  generate  a
       initramfs  capable  to  boot  live  systems,  such  as those created by
       live-helper(7). This includes the Debian Live isos,  netboot  tarballs,
       and usb stick images.

       At  boot time it will look for a (read-only) media containing a "/live"
       directory where a root filesystems (often a compressed filesystem image
       like  squashfs)  is  stored.  If  found,  it  will  create  a  writable
       environment, using aufs, for Debian like systems to boot from.


       live-boot can be configured through a boot parameter or a configuration

       To  configure the live-boot parameters used by default in a live image,
       see the --bootappend-live option in the lb_config(1) manual page.

   Kernel Parameters
       live-boot is only  activated  if  'boot=live'  was  used  as  a  kernel

       In  addition,  there  are  some  more  boot parameters to influence the
       behaviour, see below.

   Configuration Files
       live-boot can be configured (but not activated)  through  configuration
       files.  Those  files can be placed either in the root filesystem itself
       (/etc/live/boot.conf,  /etc/live/boot.d/),  or  on   the   live   media
       (live/boot.conf, live/boot.d/).


       live-boot currently features the following parameters.

           Set  the  accessibility  level  for  physically or visually impared
           users. ACCESS must be one of v1,  v2,  v3,  m1,  or  m2.  v1=lesser
           visual  impairment,  v2=moderate  visual  impairment, v3=blindness,
           m1=minor motor difficulties, m2=moderate motor difficulties.

           Set the default console to be used with  the  "live-getty"  option.
           Example: "console=ttyS0,115200"

           Makes initramfs boot process more verbose.
           Use: debug=1
           Without setting debug to a value the messages may not be shown.


           Another  form  of  netboot  by  downloading a squashfs image from a
           given url.  The fetch method copies the image to ram and the httpfs
           method  uses  fuse and httpfs2 to mount the image in place. Copying
           to ram requires more memory and might take a long  time  for  large
           images.  However,  it  is  more likely to work correctly because it
           does not require networking  afterwards  and  the  system  operates
           faster  once  booted  because  it  does  not require to contact the
           server anymore.
           Due to current limitations in busyboxs wget and DNS resolution,  an
           URL can not contain a hostname but an IP only.
           Not working:
           Also  note  that  therefore it's currently not possible to fetch an
           image from a namebased virtualhost of an httpd if it is sharing the
           ip with the main httpd instance.
           You may also use the live iso image in place of the squashfs image.

           Boot from an iSCSI target that has an iso or disk live image as one
           of its LUNs. The specified target is searched for a LUN which looks
           like a live media. If you use the iscsitarget software iSCSI target
           solution which is packaged in Debian your ietd.conf might look like
           # The target-name you specify in the iscsi= parameter
           Target <target-name>
             Lun 0 Path=<path-to-your-live-image.iso>,Type=fileio,IOMode=ro
             # If you want to boot multiple machines you might want to look at
           tuning some parameters like
             # Wthreads or MaxConnections

           Allows to  use  a  filesystem  from  within  an  iso  image  that's
           available on live-media.

           Do  not  check  that any UUID embedded in the initramfs matches the
           discovered medium. live-boot may be told  to  generate  a  UUID  by
           setting LIVE_GENERATE_UUID=1 when building the initramfs.

           If  specified,  an  MD5  sum is calculated on the live media during
           boot and compared to the value found in  md5sum.txt  found  in  the
           root directory of the live media.

           Let  you  specify  the  name(s) and the options of the interface(s)
           that should be configured at boot time. Do not specify this if  you
           want  to use dhcp (default). It will be changed in a future release
           to  mimick  official  kernel   boot   param   specification   (e.g.

           If  this  variable  is  set, dhcp and static configuration are just
           skipped and the system will use the (must  be)  media-preconfigured
           /etc/network/interfaces instead.

           If  you  specify  one  of this two equivalent forms, live-boot will
           first try to find this device for the "/live" directory  where  the
           read-only  root  filesystem  should  reside.  If  it  did  not find
           something usable, the normal scan for block devices is performed.
           Instead of specifing an actual device name, the keyword 'removable'
           can  be  used  to  limit  the  search  of  acceptable live media to
           removable type only. Note that if you want to further restrict  the
           media  to  usb  mass  storage only, you can use the 'removable-usb'

           live-boot  will  mount  the  encrypted  rootfs  TYPE,  asking   the
           passphrase,  useful  to  build  paranoid  live  systems  :-).  TYPE
           supported so far are "aes" for loop-aes encryption type.

           This way you could tell live-boot that your image starts at  offset
           BYTES  in  the above specified or autodiscovered device, this could
           be useful to hide the Debian Live iso or image inside  another  iso
           or image, to create "clean" images.

           Sets  the path to the live filesystem on the medium. By default, it
           is set to '/live' and you should not change that  unless  you  have
           customized your media accordingly.

           Set   the   timeout   in   seconds  for  the  device  specified  by
           "live-media=" to become ready before giving up.

           Instead of using the default optional file "filesystem.module" (see
           below)  another  file  could  be  specified  without  the extension
           ".module"; it should be placed on "/live"  directory  of  the  live

           This  tells  live-boot  to  perform  a network mount. The parameter
           "nfsroot=" (with optional "nfsopts="), should specify where is  the
           location  of  the  root  filesystem.   With  no args, will try cifs
           first, and if it fails nfs.

           This lets you specify custom nfs options.

           This parameter disables the default disabling of filesystem  checks
           in  /etc/fstab. If you have static filesystems on your harddisk and
           you want them to be checked  at  boot  time,  use  this  parameter,
           otherwise they are skipped.

           disables  the  "persistent" feature, useful if the bootloader (like
           syslinux) has been installed with persistent enabled.

           Do not prompt to eject the CD or remove  the  USB  flash  drive  on

           This   tells  live-boot  not  to  prompt  to  eject  the  CD  (when
           noprompt=cd) or remove the USB flash drive (when  noprompt=usb)  on

           This  parameters  allows to set a custom ramdisk size (it's the '-o
           size' option of tmpfs mount). By default, there is no ramdisk  size
           set,  so  the  default of mount applies (currently 50% of available
           RAM). Note that this option has no currently no effect when booting
           with toram.

           This parameter enables usage of local swap partitions.

           live-boot  will  probe  filesystems for persistent media. These can
           either be the filesystems  themselves,  if  labeled  correctly,  or
           image/archive files, if named correctly. Overlays are labeled/named
           either "live-rw" or "home-rw" and will be mounted on  /  or  /home,
           respectively;  snapshots  are  labeled/named  either  "live-sn"  or
           "home-sn" and will be extracted into / or /home, respectively  (see
           live-snapshot(1) for more information). Overlays are mounted before
           snapshots are extracted,  and  for  both  overlays  and  snapshots,
           "live-*"  are  handled  before  "home-*".  Overlay  image files and
           snapshot archive  files  have  extensions  which  determines  their
           filesystem    or    archive    type,    e.g.   "live-rw.ext3"   and

       persistent-encryption=TYPE1,TYPE2 ... TYPEn
           This option determines which types of encryption that we  allow  to
           be  used when probing devices for persistent media. If "none" is in
           the list, we allow unencrypted media; if "luks" is in the list,  we
           allow  LUKS-encrypted media. Whenever a device containing encrypted
           media is probed the user will be prompted for the  passphrase.  The
           default value is "none".

           If  you specify the keyword 'removable', live-boot will try to find
           persistent and snapshot partitions on removable  media  only.  Note
           that  if you want to further restrict the media to usb mass storage
           only, you can use the 'removable-usb' keyword.

       persistent-method=TYPE1,TYPE2 ... TYPEn
           This option determines which types of persistent media we allow. If
           "overlay"  is in the list, we consider overlays (i.e. "live-rw" and
           "home-rw"); if "snapshot" is in the  list,  we  consider  snapshots
           (i.e. "live-sn" and "home-sn"). The default is "overlay,snapshot".

           live-boot  will look for persistency files in the root directory of
           a partition, with this parameter, the path  can  be  configured  so
           that  you  can  have  multiple directories on the same partition to
           store persistency files.

           Filesystem changes are not  saved  back  to  persistent  media.  In
           particular,  overlays and netboot NFS mounts are mounted read-only,
           and snapshots are not resynced on shutdown.

       persistent-storage=TYPE1,TYPE2 ... TYPEn
           This  option  determines  which  types  of  persistent  storage  to
           consider  when  probing for persistent media. If "filesystem" is in
           the list, filesystems with matching labels will be used; if  "file"
           is  in  the  list,  all filesystems will be probed for archives and
           image   files   with   matching   filenames.   The    default    is

           Add  a  suffix  when searching for the image filenames or partition
           labels to use for  the  above  mentioned  persistent  feature,  the
           SUFFIX  will be added after a dash (e.g.: "live-sn" would transform
           to "live-sn-SUFFIX"). This is  handy  to  test  multiple  live-boot
           based live-systems with different persistent storage choices.

           A  path  to  a  file present on the rootfs could be used to preseed
           debconf database.

           All debian installed packages could be preseeded from  command-line
           that  way,  beware  of  blanks  spaces,  they  will  interfere with
           parsing, use a preseed file in this case.

           This option causes live-boot to reboot without attempting to  eject
           the media and without asking the user to remove the boot media.

           This   parameter  will  make  live-boot  to  show  on  "/"  the  ro
           filesystems (mostly compressed) on "/live". This is not enabled  by
           default  because could lead to problems by applications like "mono"
           which store binary paths on installation.

           If you boot with the normal quiet parameter, live-boot  hides  most
           messages of its own. When adding silent, it hides all.

           Adding  this  parameter,  live-boot  will  try  to  copy the entire
           read-only media to the specified device before  mounting  the  root
           filesystem. It probably needs a lot of free space. Subsequent boots
           should then skip this step and just specify the "live-media=DEVICE"
           boot parameter with the same DEVICE used this time.

           Adding  this  parameter,  live-boot  will  try  to  copy  the whole
           read-only media to the computer's  RAM  before  mounting  the  root
           filesystem.  This  could  need a lot of ram, according to the space
           used by the read-only media.

           By default, live-boot uses  aufs.  With  this  parameter,  you  can
           switch to unionfs.

FILES (old)

           Some  variables  can be configured via this config file (inside the
           live system).

           This optional file (inside the  live  media)  contains  a  list  of
           white-space  or  carriage-return-separated file names corresponding
           to disk images in the "/live" directory. If this file exists,  only
           images listed here will be merged into the root aufs, and they will
           be loaded in the order listed here. The first entry  in  this  file
           will  be  the "lowest" point in the aufs, and the last file in this
           list will be on  the  "top"  of  the  aufs,  directly  below  /cow.
           Without  this  file, any images in the "/live" directory are loaded
           in alphanumeric order.

           This optional file (which resides in the rootfs system, not in  the
           live  media)  is  used  as  a list of directories which not need be
           persistent: ie. their content does not need to survive reboots when
           using the persistence features.
           This  saves  expensive  writes and speeds up operations on volatile
           data such as web caches and temporary files  (like  e.g.  /tmp  and
           .mozilla) which are regenerated each time. This is achieved by bind
           mounting each listed directory with a tmpfs on the original path.












       More information about live-boot and the Debian  Live  project  can  be
       found on the homepage at <> and in the manual at


       Bugs can be reported  by  submitting  a  bugreport  for  the  live-boot
       package  in the Debian Bug Tracking System at <>
       or by writing a mail to  the  Debian  Live  mailing  list  at  <debian->.


       live-boot  was  written  by  Daniel Baumann <> for the
       Debian project.