Ubuntu Linux Live CD: Save data & desktop information on USB device

Ubuntu Linux (other Linux distro also able to save data on external USB hard disk or USB pen drive) has this nifty feature that allows saving both data and desktop settings. Update: According to official web page you need to use casper-rw lable instead of casper-cow. So make sure you use casper-rw if you are using Ubuntu 6.06 LTS "Dapper Drake" release.
a) Use other Linux computer or boot from Ubuntu Linux live CD
b) Plug USB pen or USB external hard disk
c) Open terminal (or click on Applications -> Accessories -> Terminal)
d) Find out USB device name:

$ sudo fdisk -l

Now assign special label casper-cow to your USB pen or USB hard disk (assuming that your USB device already formatted with ext2/ext3 file system):

$ sudo e2label /dev/sda1 casper-cow

If you need to format USB device use the following command, else skip to next step:
Partition USB device:

$ sudo fdisk /dev/sda

Format usb device:

$ sudo mkfs.ext3 /dev/sda1

Now assign new disk lable casper-cow

$ sudo e2label /dev/sda1 casper-cow

Now your USB pen or hard disk is ready to use.

How do I test persistent mode?

• Attach USB pen/hard disk to system.
• Boot from Ubuntu Linux Live CD
• At boot menu you need to type persistent word and press enter key to continue.

Now Ubuntu will automatically scan your USB hard disk or pen drive. It will also save data, your desktop settings (such as wallpaper or other stuff ) or applications on this device.

More about casper-cow label

Please note that casper-cow is a special label on an ext2/ext3 filesystem or partition. You need to use e2label command to assign the label on USB pen or hard disk drive. If this label found Ubuntu Linux will use the USB device to store desktop information as well as your data/applications. The idea is very simply, "you should be able to carry your desktop anywhere, anytime".