Debuntu

3. Installing Ubuntu on the USB stick

3.1. Mounting Ubuntu liveCd image

In the first place we need to mount our ubuntu iso. Depending if you have the .iso file or the CD, there is 2 different ways of mounting it.

3.1.1. Mounting from the CD

People using Ubuntu or any other user-friendly distro, might just have to insert the cd and it will be mounted automatically. If this is not the case:

$ sudo mount /media/cdrom

should mount it.

3.1.2. Mounting from an .iso image file

We will need to create a temporary directory, let say /tmp/ubuntu-livecd and then mount our iso (I will be using a feisty fawn iso).

$ mkdir /tmp/ubuntu-livecd
$ sudo mount -o loop /path/to/feisty-desktop-i386.iso /tmp/ubuntu-livecd

Once the cd image is ready, it is time to mount the newly created usb bar partitions:

3.2. Mounting the usb bar partitions

Same here, you might be able to get both your partition by simply replugging the usb pendrive, partition might appears as: /media/liveusb and /media/casper-rw. If this is not the case, then you will need to mount them manually:

$ mkdir /tmp/liveusb
$ sudo mount /dev/sdb1 /tmp/liveusb

All the partitions we need are now mounted, let’s copy the files.

3.3. Copying the files to the usb bar

Let positionned yourself on the CD image directory (in my case: /tmp/ubuntu-livecd , but it might be /media/cdrom , and copy at the root of your usb first partition:

• the directories: ‘casper’, ‘disctree’, ‘dists’, ‘install’, ‘pics’, ‘pool’, ‘preseed’, ‘.disk’
• The content of directory ‘isolinux’
• and files ‘md5sum.txt’, ‘README.diskdefines’, ‘ubuntu.ico’
• as well as files: ‘casper/vmlinuz’, ‘casper/initrd.gz’ and ‘install/mt86plus’

$ cd /tmp/ubuntu-livecd
$ sudo cp -rf casper disctree dists install pics pool preseed .disk isolinux/* md5sum.txt README.diskdefines ubuntu.ico casper/vmlinuz casper/initrd.gz install/mt86plus /tmp/liveusb/

It might complain about symbolic links not being able to create, you can ignore this.

Now let’s go to the first partition of your usb disk and rename isolinux.cfg to syslinux.cfg:

$ cd /tmp/liveusb
$ sudo mv isolinux.cfg syslinux.cfg

change /tmp/liveusb according to your settings

Edit syslinux.cfg so it looks like:

DEFAULT persistent
GFXBOOT bootlogo
GFXBOOT-BACKGROUND 0xB6875A
APPEND  file=preseed/ubuntu.seed boot=casper initrd=initrd.gz ramdisk_size=1048576 root=/dev/ram rw quiet splash --
LABEL persistent
  menu label ^Start Ubuntu in persistent mode
  kernel vmlinuz
  append  file=preseed/ubuntu.seed boot=casper persistent initrd=initrd.gz ramdisk_size=1048576 root=/dev/ram rw quiet splash --
LABEL live
  menu label ^Start or install Ubuntu
  kernel vmlinuz
  append  file=preseed/ubuntu.seed boot=casper initrd=initrd.gz ramdisk_size=1048576 root=/dev/ram rw quiet splash --
LABEL xforcevesa
  menu label Start Ubuntu in safe ^graphics mode
  kernel vmlinuz
  append  file=preseed/ubuntu.seed boot=casper xforcevesa initrd=initrd.gz ramdisk_size=1048576 root=/dev/ram rw quiet splash --
LABEL check
  menu label ^Check CD for defects
  kernel vmlinuz
  append  boot=casper integrity-check initrd=initrd.gz ramdisk_size=1048576 root=/dev/ram rw quiet splash --
LABEL memtest
  menu label ^Memory test
  kernel mt86plus
  append -
LABEL hd
  menu label ^Boot from first hard disk
  localboot 0x80
  append -
DISPLAY isolinux.txt
TIMEOUT 300
PROMPT 1
F1 f1.txt
F2 f2.txt
F3 f3.txt
F4 f4.txt
F5 f5.txt
F6 f6.txt
F7 f7.txt
F8 f8.txt
F9 f9.txt
F0 f10.txt

Woof, finally we have our usb disk almost usuable. We have a last thing to do: make the usb bootable.

3.4. Making the usb bar bootable.

in order to make our usb disk bootable, we need to install syslinux and mtools:

$ sudo apt-get install syslinux mtools

And finally unmount /dev/sdb1 and make it bootable:

$ cd
$ sudo umount /tmp/liveusb
$ sudo syslinux -f /dev/sdb1

Here we are , reboot, set your BIOS to boot from the usb bar and enjoy Ubuntu linux from a pendrive

4. Troubleshooting

If you are having trouble booting on the usb bar, this might be due to your MBR being corrupted. In order to fix it up, you can use lilo (I installed lilo on my box only for thid purpose).

$ lilo -M /dev/sdb

will fix the MBR on device /dev/sdb