Install Ubuntu from an ISO without burning to a CD/DVD

Pre-requisites and Assumptions

1) A minimum of 2 partitions in the disk with at least one partition having enough space to accommodate the downloaded distribution's ISO image. (Use graphical partition manager like gparted to create multiple partitions in case you have only a single partition machine).

To know about partitions check this link.

This partition must be mounted and not touched during the installation. Let this partition be mounted at the location PartitionU.

2) Grub Boot Loader is installed in the machine.( May work with LILO also. But i have'nt tried)

3) The RAM and other hardware requirements specified by the distribution vendor are met.

Procedure:

1) Download the ISO image of the linux distribution to the PC from the appropriate website. In my case, it is Ubuntu Jaunty Jackalope 9.04 from here

2) Navigate to the directory where the ISO is downloaded. Move the ISO image to the partition in which the distribution will not be installed (PartitionU).

3) Mount the ISO image in a mount point using the -o loop option as

# mount -o loop ubuntu-9.04-desktop-i386.iso /mnt

4) Navigate to the mounted folder using

# cd /mnt/

5) In this directory, navigate into the casper directory as

# cd casper/

6) Copy the files initrd.gz and vmlinuz to the partition directory (PartitionU)

# cp casper/vmlinuz Partition2/
# cp casper/initrd.gz Partition2/

Note: for other distributions these files may be present in a different directory instead of casper. Locate them and make appropriate changes in the steps

7) Open the grub configuration file /boot/grub/menu.lst.

# vi /boot/grub/menu.lst

Replace X,Y and Z according to your machine's partition table and add the following contents to the file menu.lst. (u will find similar entries. Append these three lines to them)

title Ubuntu 9.04 Installation
kernel (hdX,Y)/boot/vmlinuz root=/dev/Z ro
initrd (hdX,Y)/boot/initrd.img

The values of X and Y are to be chosen based on the partitions in the machine. To know about Grub naming conventions please read this.

Z may be sd(a/b/c/d) or hd(a/b/c/d) depending on whether PartitionU is on a sata/scsi or ide disk respectively. a/b/c/d denoting the primary partition number 1/2/3/4. Choose the appropriate number.

8) Reboot your machine and choose the new grub entry while booting into.

Note: On reboot, if the machine hangs with the error message "Waiting for Root File System...", the Grub entries were specified incorrectly in step 7. Boot into the right kernel, change the entries and try again.

9) During the Installation, choose "Install from Hard disk option " and also the location of the ISO image as Partition2 if asked. Make sure the partition2 containing the ISO is not touched or formatted during the installation.

10) Thats it ... Enjoy the new distribution !!! The grub entries and ISO may removed after the installation.