This guide was made for Ubuntu (Gnome). It works for Kubuntu (KDE) too, with a few exceptions
I've been able to get the Live CD boot straight into a Live session without timeout or fancy menu, optionally with a language pack installed.
Live USB (16.04)
- Mount the USB with Ubuntu installed in it
- Backup the file
syslinux/syslinux.cfg. We will modify it so we need
to replace it back if something goes wrong.
- Open the following files under syslinux directory:
syslinux.cfg and
txt.cfg
- Delete (or comment) everything in
syslinux.cfg.
The txt.cfg file has the default GRUB menu entries. Copy the live
one to syslinux.cfg:
default live
label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz.efi
append file=/cdrom/preseed/ubuntu.seed boot=casper cdrom-detect/try-usb=true persistent noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash --
You can add any specific kernel parameters needed for your device in
the append line.
- Save isolinux.cfg and boot your system using the USB. It will boot
straight to the desktop now.
Live USB (13.10)
- Mount the USB with Ubuntu installed in it
- Backup the file
isolinux/isolinux.cfg. We will modify it so we need
to replace it back if something goes wrong.
- Open the following files under isolinux directory:
isolinux.cfg and
txt.cfg
- Delete everything in
isolinux.cfg.
The txt.cfg file has the default GRUB menu entries. Copy the live
one to isolinux.cfg:
default live
label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz.efi
append file=/cdrom/preseed/ubuntu.seed boot=casper cdrom-detect/try-usb=true persistent noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash --
You can add any specific kernel parameters needed for your device in
the append line.
- Save isolinux.cfg and boot your system using the USB. It will boot
straight to the desktop now.
[source]
Live USB (11.04)
- Go to the root folder of your Live USB
- Enter the
syslinux directory
- Make the
syslinux.cfg file writeable
Replace the contents of the file syslinux.cfg with:
default live
label live
say Booting an Ubuntu Live session...
kernel /casper/vmlinuz
append file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash noprompt --
- Optional: localize the system (see below)
Live CD
If you've a Live CD in your CD drive, mount it. Otherwise, if you've an ISO file available, mount it on /media/cdrom by running the next command in a terminal (replace the name of the .iso file accordingly):
sudo mount -o loop,ro ubuntu-11.04-desktop-amd64.iso /media/cdrom
- Create a temporary directory in which the CD contents can be stored, say
~/live-cd (mkdir ~/live-cd)
- Copy the contents of the CD to the folder
~/live-cd/iso (cp -r /media/cdrom ~/live-cd/iso)
- Since the Live CD is not needed anymore, it can be unmounted (
sudo umount /media/cdrom)
- Open the
~/live-cd/iso folder (cd ~/live-cd/iso)
- Enter the
isolinux directory (cd isolinux)
- Make the
isolinux.cfg file writable (chmod u+w isolinux.cfg)
Replace the contents of the file isolinux.cfg with:
default live
label live
say Booting an Ubuntu Live session...
kernel /casper/vmlinuz
append file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --
- Optional: localize the system (see below)
Open a terminal and run:
cd ~/live-cd
chmod u+w iso/isolinux/isolinux.bin
mkisofs -r -V "Ubuntu Live session" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o ubuntu-11.04-live-amd64.iso iso
- The new iso will be available at
~/live-cd/ubuntu-11.04-live-amd64.iso. To save space, the ~/live-cd/iso directory can be removed. (rm -rf ~/live-cd/iso)
- Now burn the
ubuntu-11.04-live-amd64.iso file on a CD if needed.
Localize Ubuntu (translations)
If you want the system in the languages English, Spanish, Portuguese, Xhosa or Simplified Chinese, you've just to add the locale= boot option with en, es, pt, xh or zh to the append line as in:
... quiet splash locale=pt --
Otherwise, if you do not want to modify the file containing the root file system (filesystem.squashfs) and do not mind hacking around, continue reading.
Open a terminal and navigate to the ~/live-cd/iso directory and put the code from http://pastebin.com/VTdt9WFZ in a file (name it install-locale) and run it.
This script mounts the filesystem.squashfs, retrieves version information of the language packs from it, downloads the packages and put those in the directory locale-hack. Next, a script is created that installs the language packages on boot time. To make that work, the script also modifies the syslinux.cfg or isolinux.cfg file to apply these changes.
You'll be asked for a locale, enter something like nl or de. The script is not that clever to understand things like Dutch or German. Afterwards, the file can be removed
The terminal commands that should be executed:
cd ~/live-cd/iso
wget http://pastebin.com/raw.php?i=VTdt9WFZ -O install-locale
bash install-locale
rm install-locale
Note that adding language pack can cause the generated .iso file to be bigger than 700MB which won't fit on a CD. For virtual machines however, it suffices. This hack has as a side-effect that Plymouth does not work (i.e. you do not get a fancy boot screen), but at least the system is translated when logging in. Otherwise, you had to install language-pack-gnome-* manually.
References
Live with persistence:
You have the portability of live media with a home-folder and possibly other temp storage
Live without:
Portability but no saved anything
LiveUSB with persistence:
Less life out of the USB(a bunch more reads), but very similar to 1
LiveUSB without persistence:
Less life out of the USB(a bunch more reads), but very similar to 2
Full install:
Obviously, a full install to the USB would translate to shorter life since it would drastically increase the number of reads and writes.
Best Answer
You are running in fact Ubuntu.
There are few differences, most importantly, whenever you need to start a program, the liveCD needs to run it from the CD, which is slower. Also, you cannot save anything permanently (unless you specifically attach ie. mount your hard disk).
Finally, an installed system will be better tuned to your hardware, faster, and more up-to-date (packages on the LiveCD may be obsolete).
One caveat are proprietary drivers, notably Nvidia drivers. Nvidia drivers (which have 3D support) cannot be installed automatically by the Ubuntu installer, so if you have Nvidia, after the installation instead of the eye-candy of a 3D desktop you will have a much less eye-catching 2D desktop. However, Ubuntu will then tell you that you should install the Nvidia drivers from the Nvidia site, and you will be able to do so with a single mouse click, after which you will have your nice desktop back.
Otherwise it's pretty much the same stuff.