Why customize LiveCDs

You may wish to customise the Ubuntu Desktop LiveCD to:

  • make your own Ubuntu distribution
  • show off a particular application
  • localise to a certain language
  • remove software packages
  • add software packages
  • update software packages
  • change system defaults (theme, icons, desktop background, panels, browser homepage, etc)

How to Customise the Ubuntu Desktop CD

The easiest way to create a custom LiveCD is to use Ubuntu Customization Kit. What follows is the manual way of accomplishing the same.

IconsPage/warning.png This guide is for the Desktop LiveCD. There is another page referring to customisation of the Alternative/Server Install CD. Also, there is a guide on how to create a LiveCD from scratch.

System Requirements

  • At least 3-5 GB of free space
  • At least 512 MB RAM and 1 GB swap (recommended)
  • An Ubuntu kernel with squashfs support (present since in Ubuntu 6.06)

  • QEMU/KVM, VirtualBox or VMware for testing (optional)

  • squashfs-tools, to unpack and recompile the 'live' filesystem

  • genisoimage, to compile a new ISO image

IconsPage/warning.png The architecture (amd64 or i386) to be stored on the LiveCD should be the same as the architecture used to perform the customization. It is not trivial to customize an amd64 LiveCD using an i386 operating system, for example. Also, the Ubuntu system you are using to create a custom image should be of the the same major release version as that of the target system. Otherwise, the LiveCD may not run, and/or you may get stuck at some point during the customisation process.

Install pre-requisities

  • Make sure that you have installed the needed tools

sudo apt install squashfs-tools genisoimage

Obtain the base system

mkdir ~/livecdtmp
mv ubuntu-18.04-desktop-amd64.iso ~/livecdtmp
cd ~/livecdtmp

Note: this example refers to Ubuntu 18.04 Desktop. Replace it with the name of your iso.

Extract the CD .iso contents

Mount the Desktop .iso

mkdir mnt
sudo mount -o loop ubuntu-18.04-desktop-amd64.iso mnt

Extract .iso contents into dir 'extract-cd'

mkdir extract-cd
sudo rsync --exclude=/casper/filesystem.squashfs -a mnt/ extract-cd

Extract the Desktop system

Extract the SquashFS filesystem

sudo unsquashfs mnt/casper/filesystem.squashfs
sudo mv squashfs-root edit

Prepare and chroot

WARNING: If you do this in 14.04 LTS, you will lose network connectivity (name resolving part of it). /etc/resolv.conf is and should remain a symlink to /run/resolvconf/resolv.conf nowadays. To enable name resolving, temporarily edit that file instead. If you need network connectivity within chroot

sudo cp /etc/resolv.conf edit/etc/

On more recent releases, you can avoid this issue by just binding /run instead, which will pull your host's resolvconf info into the chroot:

sudo mount -o bind /run/ edit/run

NOTE: Recommended that you do not do this unless you know what you're doing Depending on your configuration, you may also need to copy the hosts file

sudo cp /etc/hosts edit/etc/

The remaining steps are good, unlike the ones above:

sudo mount --bind /dev/ edit/dev
sudo chroot edit
mount -t proc none /proc
mount -t sysfs none /sys
mount -t devpts none /dev/pts

The above commands will mount important directories of your host system to the edit directory. If you later decide to delete the edit directory, make sure to unmount all of them before doing so (see the Cleanup chapter below). Otherwise, your host system will become unusable until you reboot it.

To avoid locale issues and in order to import GPG keys

export HOME=/root
export LC_ALL=C




In 9.10, before installing or upgrading packages you need to run

dbus-uuidgen > /var/lib/dbus/machine-id


dpkg-divert --local --rename --add /sbin/initctl
ln -s /bin/true /sbin/initctl


To view installed packages by size

dpkg-query -W --showformat='${Installed-Size}\t${Package}\n' | sort -nr | less

When you want to remove packages remember to use purge

apt purge package-name

Custom Background for GNOME

Generally background files are located in /usr/share/backgrounds. Copy your png file there, adjust owner and file access, and edit the files:

  1. /usr/share/gnome-background-properties/ubuntu-wallpapers.xml and

  2. /usr/share/gconf/defaults/16_ubuntu-wallpapers or other files in the same directory. by changing the string /usr/share/backgrounds/warty-final-ubuntu.png to point to your file

Eventually change or add attributes to other configuration files such as: /var/lib/gconf/debian.defaults/%gconf-tree.xml or /etc/gconf/gconf.xml.defaults/%gconf-tree.xml).

Historical: More for Dapper...

Change gconf values (fonts, panels etc.)

To make any change on the gconf attributes you must add the value that you want in the file /etc/gconf/gconf.xml.defaults/%gconf-tree.xml. Adding a value in that file will change the default values of Gnome or other applications, so you can change fonts, backgrounds, themes, cursors etc.

Instead of editing the file with gedit or another text editor, you can use the gconftool-2, under the chroot environment, running the following line:

gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --type string --set yourkey "yourvalue"

where string, yourkey and yourvalue must be the type, key and value that you want to change...

Making several gconf changes

Editing gconf by setting each value separately takes too much time. There is a better way:

Make a test user and adjust the settings as you wish. Run

gconftool-2 --dump /the/settings/branch/you/need > ~/live/your-new-settings.xml
sudo chown root:root ~/live/your-new-settings.xml
sudo mv ~/live/your-new-settings.xml ~/live/edit/your-new-settings.xml

and then, in the chroot environment, run

gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --load /your-new-settings.xml
rm /your-new-settings.xml

This way you can import the whole branch, e.g. /apps/panel - all settings for Gnome's panels. Note that this way you import not only the keys, but also their descriptions, so all GConf descriptions will be changed to the language which was set for the test user, and there will be no way to safely change them back. Some programs (for example, keyboard shortcuts in Preferences menu) use descriptions from GConf.

Setting regional defaults

Legacy Boot

Change default language of gfxboot

This customization must be done outside the chroot.

sudo apt install dpkg-dev uck
apt source gfxboot-theme-ubuntu gfxboot
cd gfxboot-theme-ubuntu*/
sudo cp -af boot/* ../extract-cd/isolinux/

Change "fi" to your preferred locale. Note that this does not change which languages are available in the F2 menu. For more info about gfxboot customization, see Ubuntu Customization Kit.

  • A other way to change the default language of gfxboot without rebuild the packages is to create a file name lang in the isolinux directory containing your locale's name.

Change default keyboard

In 12.04, changing the default keyboard for a live boot is not as obvious as it used to be in 10.04 and earlier. As an example, if you want to keep the default language as English but set the default keyboard to "GB", you are going to have to edit the file /usr/lib/ubiquity/ubiquity/misc.py. If you look at the hard-coded defaults table at around line 620 it should be fairly obvious what's going on...

// In /usr/lib/ubiquity/ubiquity/misc.py line 620:
    default_keymap = {
        'ar': 'ara',
        'bs': 'ba',
        'de': 'de',
        'el': 'gr',
        'en': 'us',

You can se the default keymap for your default language by editing this table, but remember that if you update the ubiquity package on your image then any changes will be clobbered.

Also note this only works for X. To set the console keyboard:

dpkg-reconfigure keyboard-configuration


UEFI booting uses GRUB instead of gfxboot. There's no options for changing the language or keyboard for the live session, so it's all English by default. Therefore GRUB configuration needs to be modified. In the Ubuntu Finnish Remix script this is done as follows:

sed -i '6i    loadfont /boot/grub/fonts/unicode.pf2' boot/grub/grub.cfg
sed -i '7i    set locale_dir=$prefix/locale' boot/grub/grub.cfg
sed -i '8i    set lang=fi_FI' boot/grub/grub.cfg
sed -i '9i    insmod gettext' boot/grub/grub.cfg
sed -i 's%splash%splash locale=fi_FI console-setup/layoutcode=fi%'
sed -i 's/Try Ubuntu without installing/Kokeile Ubuntua asentamatta/'
sed -i 's/Install Ubuntu/Asenna Ubuntu/' boot/grub/grub.cfg
sed -i 's/OEM install (for manufacturers)/OEM-asennus
(laitevalmistajille)/' boot/grub/grub.cfg
sed -i 's/Check disc for defects/Tarkista asennusmedian eheys/'
mkdir -p boot/grub/locale/
mkdir -p boot/grub/fonts/
cp -a /boot/grub/locale/fi.mo boot/grub/locale/
cp -a /boot/grub/fonts/unicode.pf2 boot/grub/fonts/

Customization limits

After customization make sure that there are no users with an UID == 999. Otherwise your image won't boot because no initial user is available (see /usr/share/initramfs-tools/scripts/casper-bottom/25adduser, -> 'db_set passwd/user-uid 999'). This may happen, for example, after installing VirtualBox/GuestAdditions

While in chroot:

awk -F: '$3 == 999' /etc/passwd

If you get any hits, try changing the uid:

usermod -u 500 $hit

Miscellaneous Defaults

You may wish to edit the files in /etc/default to change system behavior at startup. You might also edit /etc/profile, /etc/bash.bashrc, and /etc/bash_completion to change login settings for all users on the system. You cannot directly edit defaults for the live cd user (e.g., casper, ubuntu, or user) since that account is created at boot time. You can directly edit root's default files (/root in the chroot environment).

If you wish to change the default timezone used by the live cd, run:

dpkg-reconfigure tzdata

If you have added a locale and wish to make it the default, update /etc/default/locale. You may have to compile the locale:

locale-gen new_locale
update-locale LANG=new_locale LANGUAGE=new_locale LC_ALL=new_locale

These changes must be made as root in the chroot environment.

Advanced Customizations

Live CD Kernel

If you want to customize further the boot process, you can change the livecd kernel, by copying the vmlinuz and initrd you want in place of the ones you find in extract-cd/casper.


sudo cp edit/boot/vmlinuz-2.6.15-26-k7 extract-cd/casper/vmlinuz
sudo cp edit/boot/initrd.img-2.6.15-26-k7 extract-cd/casper/initrd.gz

Note that the initial ramdisk filename for newer releases (since 9.10) is casper/initrd.lz (not .gz).

Removing the (Casper) Autologin

The autologin feature of the Jaunty/9.04 live CD is a bit of an on-the-fly boot-hack. After extracting the initrd.gz, you need to edit the casper-bottom/25configure_init script and then recreate the initrd.gz file, replacing the original in extract-cd/casper. The process to do so goes like this:

# cd extract-cd/casper
# mkdir tempdir
# cd tempdir
# gunzip -dc ../initrd.gz | cpio -imvd --no-absolute-filenames
# cp scripts/casper-bottom/25configure_init scripts/casper-bottom/25configure_init.orig
# vi scripts/casper-bottom/25configure_init

Now look for line 25 which has the conditional statement to test $USERNAME.

Line 25 performs a conditional evaluation and if it evaluates to true, it will execute the code within the if block. The if block contains code to modify files used in the boot process to create the live cd autologin.

To disable the autologin feature, Remove $USERNAME, but just leave the quotes. The -n modifier tests the $USERNAME string to see if it's length is non-zero. By removing the variable, and leaving two double quotes, this statement evaluates to false because the two double quotes effectively make a zero-byte string. Be sure to leave no whitespace between the quotes because whitespace will make the evaluation true and execution wil fall into the if block.

21:log_begin_msg "$DESCRIPTION"
23:# Arrange for shells on virtual consoles, rather than login prompts
25:if [ -n "$USERNAME" ]; then

After making the change, line 25 will look like this:

25:if [ -n "" ]; then

Save the file and quit the editor. Then, from extract-cd/casper/tempdir run the following command to re-create the initrd.gz file. There are other methods for re-creating the initrd.gz file on this page which may work also.:

# cp ../initrd.gz ../initrd.gz.orig
# find . | cpio -o -H newc | gzip -9 > ../initrd.gz

This will create a new initrd.gz file with no auto login. You can then continue to remaster the CD as described on this page. Be sure to create a user and password to login with before you remaster the cd. If you do not, you will not be able to login after booting!

Also, I have read a few articles mentioning that Karmic (9.10) uses initrd.lz instead of initrd.gz. I do not know if this is true, but should mention it in case you are not getting the expected results. To unpack the initrd.lz file, you need to do this:

# cd extract-cd/casper
# mkdir lztempdir
# cd lztempdir
# lzma -dc -S .lz ../initrd.lz | cpio -imvd --no-absolute-filenames

And to re-create the initrd.lz file:

# cp ../initrd.lz ../inird.lz.orig
# find . | cpio --quiet --dereference -o -H newc | lzma -7 > ../initrd.lz

Boot init

You have to edit the files in edit/usr/share/initramfs-tools/scripts/casper-bottom/* For example you can change the hostname or the livecd user.


sudo nano edit/usr/share/initramfs-tools/scripts/casper

and edit the username or hostname

sudo nano edit/usr/share/initramfs-tools/scripts/casper-bottom/10adduser

to edit even the livecd user's password.

If you're customizing 10.04, you need to edit variables in /etc/casper.conf for the user and host names instead of modifying the scripts

P.S. in order to obtain an encrypted password, you have to use the mkpasswd program that's shipped with whois package!

Rebuilding initrd

After you've modified the kernel, init scripts or added new kernel modules, you need to rebuild the initrd.gz file and substitute it into the casper directory.

sudo chroot edit
mkinitramfs -o /initrd.gz 2.6.15-26-k7

(replace the kernel version with the one that the CD will boot with - this can be found in edit/lib/modules) *** do I need to mount proc, sys, devpts after chroot here ? Gordon

Exit from the chroot jail and move this file to extract-cd/casper:

mv edit/initrd.gz extract-cd/casper/


Be sure to remove any temporary files which are no longer needed, as space on a CD is limited. A classic example is downloaded package files, which can be cleaned out using:

apt clean

Delete temporary files

rm -rf /tmp/* ~/.bash_history

WARNING: See note earlier about resolv.conf, do not remove it in 14.04 LTS anymore or even in 12.04 LTS. Or nameserver settings

rm /etc/resolv.conf

If you installed software, be sure to run

rm /var/lib/dbus/machine-id


rm /sbin/initctl
dpkg-divert --rename --remove /sbin/initctl

from within the chroot environment.

Now unmount all special filesystems and exit the chroot

umount /proc || umount -lf /proc
umount /sys
umount /dev/pts
umount /dev

WARNING: If /dev fails to unmount, do not try to force it, or you will experience major issues. Instead, make sure no processes in the edit directory are running, then retry the 'umount /dev' command from within the chroot. If it still fails, you will have to restart your computer to get rid of it.

Producing the CD image

Assembling the file system

Regenerate manifest

chmod +w extract-cd/casper/filesystem.manifest
sudo su
chroot edit dpkg-query -W --showformat='${Package} ${Version}\n' > extract-cd/casper/filesystem.manifest
sudo cp extract-cd/casper/filesystem.manifest extract-cd/casper/filesystem.manifest-desktop
sudo sed -i '/ubiquity/d' extract-cd/casper/filesystem.manifest-desktop
sudo sed -i '/casper/d' extract-cd/casper/filesystem.manifest-desktop

Compress filesystem

sudo rm extract-cd/casper/filesystem.squashfs
sudo mksquashfs edit extract-cd/casper/filesystem.squashfs -nolzma
  • Note: The -nolzma option is only available from Hardy , and was removed in Karmic. Also, the squashfs has to be generated using a version of mksquashfs that is compatible with the kernel used on the CD you are customizing. For example, you cannot generate a jaunty squashfs on karmic, as the jaunty kernel is not able to mount a squashfs prepared using mksquashfs from karmic.

For slightly higher compression at the cost of compression time, you can increase the block size:

sudo mksquashfs edit extract-cd/casper/filesystem.squashfs -b 1048576

For a highest possible compression at the cost of compression time, you may use the xz method and is better exclude the edit/boot directory altogether:

sudo mksquashfs edit extract-cd/casper/filesystem.squashfs -comp xz -e edit/boot

Update the filesystem.size file, which is needed by the installer:

sudo su
printf $(du -sx --block-size=1 edit | cut -f1) > extract-cd/casper/filesystem.size

Set an image name in extract-cd/README.diskdefines

sudo vim extract-cd/README.diskdefines

(you can use "sudo nano extract-cd/README.diskdefines" if you have difficulties understanding vim)

Remove old md5sum.txt and calculate new md5 sums

cd extract-cd
sudo rm md5sum.txt
find -type f -print0 | sudo xargs -0 md5sum | grep -v isolinux/boot.cat | sudo tee md5sum.txt

Create the ISO image

sudo mkisofs -D -r -V "$IMAGE_NAME" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o ../ubuntu-9.04.1-desktop-i386-custom.iso .

Testing the CD

Test using qemu emulator

qemu -cdrom ubuntu-9.04.1-desktop-i386-custom.iso -boot d -m 512

Or if you have hardware acceleration for kvm

kvm -cdrom ubuntu-9.04.1-desktop-i386-custom.iso -boot d -m 512

You can also test with virtualbox-ose, which is free software and available in the Ubuntu universe repository.


Some experience problems virtualizing the iso after changing the livecd linux kernel. If you do, go click F6 when the boot screen is showing. Move the cursor between splash quiet and -- and write: all_generic_ide

Burning the image to CD

Simple! Just do

cdrecord dev=/dev/cdrom ubuntu-9.04-desktop-i386-custom.iso

Additional uses for the image

Install Ubuntu from a USB stick

Installation From Image Loaded On Hard Drive


If you have any comments or questions, please feel free to add them here.

If you are answering a question, please rewrite the question into a tip that answers the question. (to help keep things to the point.)

New questions at the bottom (I guess.)

I have created an small Customization Example (named Firebird Live CD) by adding an firebird2.1-superand flamerobin packages (this apply to ubuntu Hardy Heron also it was tested with xubuntu 8.04) http://flamerobin.blogspot.com/2008/08/creating-flamerobinfirebird-livecd-with.html

Warning: qemu did not work for me as given in the guide above. Even the normal 8.04 live cd would not boot correctly. Every time, I would get thrown into the ash shell (busybox, initramfs) and while there, a "cat /casper.log" would reveal that it was "Unable to find a medium containing a live filesystem". Just use virtualbox-ose. It actually works with virtualbox. However, after using apt to install virtualbox-ose, I had to run "sudo depmod" again in order for the vboxdrv module to be found by modprobe. Hope that helps!


Warning: Squashfs is currently in development and is thus not finalized as a format. This means you cannot assume a filesystem.squashfs created using the Ubuntu 9.04 version of makesquashfs will be compatible with the squashfs drive an older live CD. I was customizing an Ubuntu 7.10 LiveCD and when testing it always booted it an (initramfs) prompt--the squashfs was not getting mounted as /. I had to build from within an Ubuntu 7.10 chroot to get it to work.


I have created an small Customization Example (named Firebird Live CD) by adding an firebird-super-server and flamerobin packages (this apply to ubuntu dapper drake) http://flamerobin.blogspot.com/2006/05/creating-flamerobinfirebird-live-cd.html I created an updated guide with Ubuntu Festy Fawn also with an iso download for the Firebird/Flamerobin live cd http://flamerobin.blogspot.com/2007/09/creating-flamerobinfirebird-livecd-with.html

I have created tool for automatic remastering of live CD images. See http://uck.sourceforge.net/ .


  • GUI for simple creation of localized CDs (including changing gfxboot and installing language packs)
  • Script for customization of ISO, SquashFS and initrd on live CD.

http://www.atworkonline.it/~bibe/ubuntu/custom-livecd.htm seems to have some nice info. no license that I can see so we would need to ask permission from the author to us its material.

If you want to make the CD boot faster, you might try sorting the files so that they are in the CD in the order that they are accessed: http://lichota.net/%7Ekrzysiek/projects/kubuntu/dapper-livecd-optimization/

Great How To. I am having one issue however. I would like to use custom xorg.conf and sources.list files. Any tips on doing this? Thanks.

  • Simply, copy the files to edit/etc/ in the same way (and at the same time) that you copy in the resolv.conf and hosts files.
  • I have found that copying xorg.conf doesn't work, as the boot-time scripts overwrite it. Besides, you can't guarantee that a particular xorg.conf will run on all hosts. I'm currently trying to get the binary NVIDIA drivers to work out of the box if an NVIDIA card is present. If I figure out how to fix the xorg.conf, I'll post it here. --JeremyVisser

I've managed to get Synaptic running from within the chroot environment, but it does hang when I try to apply packages. What you do is run "Xnest -ac :1" to get an Xnest server to run on display :1 without access control so anyone can connect to it. Then, in the chroot environment, run "export DISPLAY=:1" to get programs to use the display. Then, type "metacity &" to be able to move windows. Finally, run "synaptic".

It works fine until you try to apply packages, where it hangs for me. --JeremyVisser

Shouldn't the mkinitramfs command use the casper scripts, like "mkinitramfs -o initrd.gz 2.6.15-23-386 -d /usr/share/initramfs-tools"?

There are tricks on how you can get to feel the GNOME system in your chroot environment.

1. Copy your xorg.conf in the chrooted "etc/X11/" directory.

cp /etc/X11/xorg.conf edit/etc/X11/

2. Create generic devices on your chroot system using MAKEDEV

cd /dev/
MAKEDEV generic

3. Start X or restart gdm

/etc/init.d/gdm start

Supposed you want to make modifications on the Desktop, that will be used by all the new users, just change your $HOME to /etc/skel/ and start gdm or X.

export HOME=/etc/skel/

If you want to load all the other stuff GNOME needs (i.e, dbus, avahi, network-manager), just boot as (single-user mode), and start dbus in your chrooted environment.

/etc/init.d/dbus start

An example of the whole procedure. (under single-user mode)

sudo /etc/init.d/networking restart
sudo nano /run/resolvconf/resolv.conf # See notes about resolv.conf earlier this page. Add temporarily eg. nameserver, but do not touch /etc/resolv.conf in any way
sudo cp /etc/X11/xorg.conf edit/etc/X11/
sudo chroot edit
mount -o none /proc
mount -o none /sys
export HOME=/etc/skel/
cd /dev/
MAKEDEV generic
/etc/init.d/dbus start
/etc/init.d/gdm start

--- joelbryan


I am about to build a new Livecd and have a question: When I change the username, hostname and the user's password the user login automatically during booting the livesystem. But this is not desired. Is it correct, that I have to enter a password under a Desktop LiveCD when I delet the encrypted password in /usr/share/initramfs-tools/scripts/casper-bottom/10adduser ?


Changing username and password will not change login behaviour, because this is done in /usr/share/initramfs-tools/scripts/casper-bottom/15autologin

--- Alexander Hosfeld

Having trouble starting a MySQL server from within the chroot jail. Any suggestions?

- Dave


I am trying to make a customized live cd of Kubuntu 6.06 that will be completly preconfigured, so that when the user clicks on the install icon on KDE the installer should do everything by itself, meaning that the installer should not ask any questions to the user.

To do this I am trying to write a preseed file to tell the installer the information that it needs.

The problem is that even with this preseed file I could only tell the installer what is the username that it should use, the rest of the information is simply ignored by the installer.

I must be doing something wrong and would appreciate any and all help given me.

Thanks, Komyg

PS: Should I post my preseed file here?

If the livecd is not going to be used for the purposes of installing what files can be removed? Can the "pool" files containing the .debs be removed too?

- Mike

If I want to put in my LiveCD applications that aren't in the sources.list (like ooffice 2.2 or perl audio converter), what cain I do?

- Isoldanne

When you're in the chroot you can install applications just like you would on a live system. If you install from source you can feel free to delete the source tarbal and make folders after you do 'make install'.

- Bob/Paul

To get desired /etc/X11/xorg.conf one can modify the /usr/bin/dexconf. This script generates xorg.conf automatically in liveCD session according to the booted machine.

For example:

# diff ~/bin/dexconf /usr/bin/dexconf
<       Option          "XkbLayout"     "us,il"
<       Option          "XkbOptions" "grp:alt_shift_toggle,grp_led:scroll"
>       Option          "XkbLayout"     "$XKB_LAYOUT"

-- yotam

I cant do chroot. When i run it a get this error

chroot: cannot run command `/bin/bash': No such file or directory

Please help me out

  • I had the same problem because the filesystem that I was working on was FAT32 instead of EXT2 or EXT3. Because of that, /bin/bash was not an executable I guess. If that is your case also, then please try again on a partition that is EXT2 or EXT3 (the Linux type of partition). Good luck, --vvim

Hi, I've created a simple script to ease remastering the Kubuntu Live CD. It uses aufs to avoid copying all the files back and forth.

Maybe it will be usefull to others too. The script must be run as root.

CD="${1:-kubuntu-9.04-desktop-i386.iso}" ; shift
# exit after any error:
set -e

which mkisofs mksquashfs tempfile sed

WDIR=`mktemp -d $PWD/kubuntu-remastered.XXXXXXXXXX`
function addExit {
    EXIT="$@ ; $EXIT"
function mnt {
    local margs="$1" ; shift
    local mp="$WDIR/$1"
    for D in "$@" ; do
        mkdir -v -p "$WDIR/$D"
    mount -v $margs "$mp"
    addExit "umount -v $mp"

# mount the CD image
mnt "-t auto $CD -o loop,ro" cd

# mount compressed filesystem
mnt "-t squashfs $WDIR/cd/casper/filesystem.squashfs -o ro,loop" sq

# create joined writable filesystem for the new CD
mnt "-t aufs -o br:$WDIR/cd-w=rw:$WDIR/cd=ro none" cd-u cd-w

# create joined writable filesystem for the new compressed squashfs filesystem
mnt "-t aufs -o br:$WDIR/sq-w=rw:$WDIR/sq=ro none" sq-u sq-w

echo ">>> Updating CD content"

    cd sq-u

    # ...
    # ...


echo ">>> Compressing filesystem"
mksquashfs $WDIR/sq-u/ $WDIR/cd-u/casper/filesystem.squashfs -noappend

echo ">>> Recomputing MD5 sums"
( cd $WDIR/cd-u && find . -type f -not -name md5sum.txt -not -path '*/isolinux/*' -print0 | xargs -0 -- md5sum > md5sum.txt )

echo ">>> Creating ISO image $ISO"
mkisofs \
    -V "Custom KUbuntu Live CD" \
    -r -cache-inodes -J -l \
    -b isolinux/isolinux.bin \
    -c isolinux/boot.cat \
    -no-emul-boot -boot-load-size 4 -boot-info-table \
    -o "$ISO" \

# The trap ... callbacks will unmount everything.

--- Petr Pudlak

  • Petr - this looks interesting. How do you use it? When I run it, I get ./fix-live-cd.sh: 1: shift: can't shift that many. -- Jeff

I need to know how to configure the live cd so that it does not use SWAP!

Please help me!

-- iceman

Hi, I've been experiencing problems with aptitude and I'm pretty sure its because I'm doing all this stuff on NTFS partition (according to this thread http://ubuntuforums.org/showthread.php?t=521905). But I have no other choice,coz' I've got less then 1,7GB on my ext3 partition. Any suggestion ? THX

Error messages I've been getting, when trying to install or update aptitude:

"E: Couldn't make mmap of 25165824 bytes - mmap (19 No such device) W: Unable to munmap E: The package lists or status file could not be parsed or opened."

-heethen (heethen at centrum dot cz)

I would suggest creating an ext3 filesystem within your NTFS partition. To create the file, type

dd if=/dev/zero of=/mnt/hda1/workspace.img bs=1024 count=$((1024*1024*15))

Where I assumed your NTFS partition was on hda1, and you wanted to call the new filesystem workspace.img (it's really just a file within NTFS), and that you wanted 15Gb of room to work. (You don't need that much, but with 15Gb you should have plenty of room.) Then you format the new filesystem with the command

sudo /sbin/mkfs.ext3 /mnt/hda1/workspace.img

then create a mountpoint

sudo mkdir /mnt/workspace

then mount the new filesystem

sudo mount -o loop /mnt/hda1/workspace.img /mnt/workspace

You can then use as much space on the NTFS partition as you want, and have all the benefits of ext3 (like getting the *** thing to work). --Tom

Editing gconf by setting each value separately takes too much time. There is a better way:

Make a test user and adjust the settings as you wish. Run

gconftool-2 --dump /the/settings/branch/you/need > ~/live/your-new-settings.xml
sudo chown root:root ~/live/your-new-settings.xml
sudo mv ~/live/your-new-settings.xml ~/live/edit/your-new-settings.xml

and then, in the chroot environment, run

gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --load /your-new-settings.xml
rm /your-new-settings.xml

This way you can import the whole branch, e.g. /apps/panel - all settings for Gnome's panels.

---Jacob Popov ubuntu-9.04-desktop-i386.iso

Is there no way to copy the user's gconf-values to the default gconf-values in the chrooted environment? This would be a lot easier than writing commands.

It took me a long time to find the details for configuring a static IP on the live CD without doing it in the root file system. This enables you to create a few boot options with different static details and a DHCP on but all from the same rootfs.

There is a casper parameter which is in the form:




I think I have discovered how to do this:

1) Edit accordingly /usr/share/initramfs-tools/scripts/casper-bottom/23networking

2) Run update-initramfs -u -k $version

- Robert

In order to get the livecd to boot from a static address found in the /etc/network/interfaces file.

I edit the /etc/network/interfaces file and add a static address for the interface eth0.

auto eth0
iface eth0 inet static
address 10.xxx.xxx.xxx
gateway 10.xxx.xxx.1

edit somepath/isolinux/text.cfg add ip=frommedia after splash

label live
  menu label ^Try Ubuntu without any change to your computer
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.gz quiet splash ip=frommedia --

This was a little hard to find. Thanks Robert Nicholas A. Schembi Pittsburgh PA USA

I've tried installing adobe flash player but while it installs fine on chroot, and then shows as installed when booting from CD. Firefox thinks it is not installed and I need to install it manually. Anybody come upon a similar problem

I tried to customize Ubuntu Hardy by installing the RT kernel and did the changes as written in the howto... it goes well, but booting in vbox is really slow. What could be the cause? I tried is once again and also in another vbox installation, but still that problem. Would be nice if someone can point me to an solution! thanks in advance see also thread: http://ubuntuforums.org/showthread.php?p=7334890#post7334890 edit: I think it has something to do with the fact that it is an RT kernel (from Hardy) ... Someone with experience with adding custom RT kernels?

I wrote a script to automate the extraction / chroot / regeneration processes: http://david.decotigny.fr/wiki/wakka.php?wiki=RemasterUbuntu . It has been tested on a jaunty x86_64 host for a jaunty i386 CD image.

-- DavidDecotigny

To put the default user in the "video" group,

printf "\nADD_EXTRA_GROUPS=1\nEXTRA_GROUPS="video"\n" >> /etc/adduser.conf 

-- CarlKarsten

In order to edit a Karmic LiveCD in any release prior to Karmic, it looks like you will need to upgrade squashfs-tools to support SquashFS v4.0:

root@maxwell:/home/Z_Custom# unsquashfs mnt/casper/filesystem.squashfs
Filesystem on mnt/casper/filesystem.squashfs is (4:0), which is a later filesystem version than I support!

I installed squashfs-tools_4.0-1 from the Karmic release into my Intrepid installation and it seems to be fine now. Maybe we should update these directions to reflect that?


--John D. Zollo

Hi.. How can I add an a Post Installation script? I mean, I want to execute a script just after the installation process. THis script is simple and set a few things to customize the installation.

Any ideas?

Best Regards

-- Alejandro

Hallo, I'm trying to remaster ubuntu 9.10 livecd. I'm following instruction from this page. When I'm trying to boot from customized system it's seems I can't login to the system, so I can't got the system running.

I am following instruction from limitation part about user id. And make sure there are none of users has uid more then 999. But, after making the squashfs file system I got a message that told me about a user with uid 1000. Actually my host system has a user with uid 1000. I'm using this user to remaster ubuntu livecd.

Does my uid (1000) that I used for remastering the livecd make the new live cd can't login? If it does, how to fix it? Am I must use another user with uid less then 999 to remaster the livecd?

Best Regards


Hello, what is the best way to remaster the Karmic release LiveCD (in VirtualBox) to include all the latest updates (more than 150) including new kernel and udev? The kernel changed from 2.6.31-14 to 2.6.31-16 and also udev.

apt autoremove removes the old headers, but I have to purge the old kernel manually (apt purge linux-image-2.6.31-14-generic).

The first problem is, update-initramfs -u -k all still runs for the old kernel, too. Only aptitude reinstall udev seems to stop this (depmod -a && dpkg --configure -a && dpkg-reconfigure udev does not help).

The second problem is, how do I prepare initrd and isolinux to run and install from a subdirectory (to create a multi-boot DVD)? The base of the DVD is Ubuntu, so / contains ubuntu-9.10-desktop-i386.iso, /kubuntu contains kubuntu-9.10-desktop-i386.iso and so on. Most things run fine when I introduce the prefix to scripts/casper and /isolinux/text.cfg:

append  file=/cdrom/preseed/kubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --


append  file=/cdrom/kubuntu/preseed/kubuntu.seed boot=casper initrd=/kubuntu/casper/initrd.lz quiet splash --

But the prefixed distributions show only an Install Ubuntu 9.10 link on the desktop, not Kubuntu (Xubuntu, LUbuntu, ...).

Thanks, René Leonhardt


I was hoping to be able to remaster the Ubuntu Live disc so that I can stick it into almost any computer, have it boot up but NOT go into the GUI, just auto login and run a media player with arguements (like a stream address). Was hoping to be able to make my own easy internet radio appliance. Give old pentium computers with soundcards to businesses and they can play my station on their PA for free!

-- Matt

I updated the Karmic Live CD with the latest updates inside chroot using aptitude with update, dist-upgrade, purge linux-image-2.6.31-14-generic, install zsh zsh-doc, install ubuntu-restricted-extras, and enabled DVD playback.

The resulting iso file turned out larger than a CD, and I put it on a USB Disk. The system boots fine, has the latest updates and can play restricted formats 'out of the box'. When I travel, I can just carry a USB Disk instead of a computer!

All releases including Ubuntu 9.10 Karmic Koala now have newer kernels available via updates. The kernel in the live CD *MUST* match the ones inside squashfs. If it does not, you get strange problems (like the wireless interface not being detected or CDs not being recognized)

i.e. for Karmic

sudo cp edit/boot/vmlinuz-2.6.31-16-generic extract-cd/casper/vmlinuz
sudo cp edit/boot/initrd.img-2.6.31-16-generic extract-cd/casper/initrd.gz

Since Karmic uses initrd.lz, I had to uncompress the .gz file and put it back in .lz format.

cd extract-cd/casper
sudo mv initrd.lz inird.lz.orig
gzip -dc initrd.gz | sudo lzma -7 > initrd.lz
cd ~/live

To conserve space, you can remove the original initrd files before changing the directory back

sudo rm -f inird.lz.orig initrd.gz

Best, Pradeep Sekar

I have a few questions, I am remastering a copy of 9.04 for a community school program i ran into a few problems

#1 how do you remove the option to update to 9.10 in the update manager #2 how do you get the CD to be recongnized in ubiquity installer as the named distro instead of ubuntu 9.04 (when i go to reinstall the softare still says it is a ubuntu 9.04 cd) #3how do you install a new kernel into the live cd and install part, i was able to upgrade it to 28.18 but when i try putting 31 on it ...it just wont boot.

#4 i have a repos server, i edit the sources.list but ubuntu repos are still the primary, how do i change that over?

#5 finally, i took out gnome games, and i want to add a list of eduacational games, but i want that as a optional install. (some computers won have game son there) is there a way to add the /.Games folder without actaully having data in it? i tried doing this in the chroot adn root menu and it still does not show up on install...

Thank you


Can anyone tell me how I can take out the option of installing the Live CD at boot. I just want them to be able to use it, not install.



You can edit the boot options in extract-cd/isolinux/text.cfg Delete all lines and sub-lines of a label you don't like: For example you can delete:

label live-install
   menu label ^Install Ubuntu
   kernel /casper/vmlinuz
   append  file=/cdro...

-- jancelis

To remove the autologin, you make us work in the extract-cd directory. Does this mean that this process has to be the last one ? Do we have to do it after all the modifications on the edit directory ? Do we have to first create the new user in the chroot ? thx --lsga

I'm having trouble properly adding a repository. How do you add one to a live cd? --Muscovy

Hi, I'm working on a unnattended install CD using Ubuntu Lucid 10.04, and I found that if you erase /sbin/initctl the automatic install doesn't run. Also the instruction to generate the initctl using dpkg-divert is not working. So be careful...


I customize the live cd and install apache2 , webmin ,,, but how to make it start after the automatic-login ?


I use a version of Ubuntu that does not automatically Start the graphical system (startx command) How can I add that to be run at boot?


I am currently working on a minor update given 10.10 is out. Unfortunately, I got held up and now time has run out. Mainly I wanted to make the scripts more copy/paste friendly. So I added a few env-variables and use those throughout the script. I've done the replacements already, but I didn't get aroud to do some testing.

In the meantime, I'll dump my current version into the above link to save my work.


aptitude can't purge packages.

The program 'aptitude' can be found in the following packages:

  • aptitude
  • aptitude-gtk (You will have to enable component called 'universe')

Try: apt install <selected package>

Unable to find a medium containing a live file system (SOLUTION)

When creating a live-usb with Unetbootin from Windows (Vista/7) you sometimes get this error. A friend of mine suggested another solution than all of the above. Create the USB stick with Unetbootin from a Linux (Ubuntu) box and NOT a windows system. Apparently something is different between the two because now my system just boots flawlessly!


Regarding the "Unable to find a medium containing a live file system"--

I had this same problem when trying to install Ubuntu 10.04, 10.10, and 10.10 netbook edition on a netbook using a USB stick. I tried creating all three using 10.10's boot disk creator, 11.04's boot disk creator, Unetbootin on 11.04, and Unetbootin on Windows 7. In all cases, I was able to make it to the usb boot menu and would select 'Install'. The Ubuntu logo would show that it was processing for a while and then fail with the above message in a terminal.

In the end, it wasn't a problem with the iso or the created USB stick. The USB drive just wasn't mounted (or would become unmounted after I tell it to go through the 'Install' procedure. Since I couldn't figure out how to boot the usb from the provided terminal, I just tried removing and reinserting the USB drive once I saw the Ubuntu logo and the progress blips.

I was able to get past this problem twice, so far, with this solution.


For all of you semi new maybe not quite as knowledgeable Ubuntu users, as myself, the live CD environment does not utilize all of the typical repositories that it would as if you installed it. You might need to add the particular repository of interest to install a program for your live CD.

For instance, I wanted to create a live CD with dcfldd on it. I had to edit etc/apt/sources.list within the chrooted environment to add the universe repository. I uncommented the following to lines in etc/apt/sources.list to install dcfldd:

deb http://archive.ubuntu.com/ubuntu natty universe
deb-src http://archive.ubuntu.com/ubuntu natty universe

Then just updated apt and installed as normal:

apt update
apt install dcfldd

Sorry if everyone already knew this. I just figured it may be helpful to users like myself.


Hi Smile :) I'm sure people appreciate comments such as your MrGrant. Otherwise people might feel they are the only ones suffering from something or maybe feel they are to blame.

On a normal LiveCd there is an "installer" icon. DOes anyone know how i can get that icon onto a normal Ubuntu desktop? I have done a full install to a large usb-stick and installed things like "GPartEd" but i definitely miss havign that installer icon & functionality. Regards from Tom Smile :)

I am looking to update or see an update to this guide that addresses a custom launcher on unity. So the idea is once the desktop and unity have resolved to the scree, I can click on a custom launcher with out looking in dash to find it. This message should be replaced with this information, in case someone else beats me to the punch.


I am a total beginner. How do I take my current computer configuration and turn it into a install CD? Thanks!

Nick Smile :) (Sorry if my question sounds dumb)

Hi Nick :)
This link might help

but i would avoid it. It's not dumb, just tricky.

Instead you can back-up all your settings, config files/folders and data by backing up the /home folder. You can move your /home to a new partition to separate your data (including configs and stuff) from the Operating System. That allows you to re-install the OS without messing anything up

It's even possible to have 2 different Operating Systems sharing the same /home although it's not recommended.

Better places to ask questions are

and Launchpad
Regards from
Tom Smile :)

I think this entry could be improved by adding some explanation of what we are trying to accomplish with these commands. Pretty much any time it says "you need to use" or "remember to" it would be great to know why. Just my two cents.


"Unable to find a medium containing a live file system" when have customized LiveCD image.

I conveniently missed this step from the main document "Recognition as an Ubuntu Remix": https://help.ubuntu.com/community/LiveCDCustomizationFromScratch#Recognition_as_an_Ubuntu_Remix

As scripts/casper-bottom/41apt_cdrom script from initram image looks for ".disk/info" to recognize the Ubuntu image. If this file does not exist or is zero size on the DVD image, initramfs tools will not mount the CDROM/USB.

if [ ! -s /root/cdrom/.disk/info ]; then

  • exit 0




LiveCDCustomization (last edited 2020-01-29 09:44:51 by akrosikam)