Step 1: Upgrade your existing Ubuntu
First for all, upgrade your existing Ubuntu to Ubuntu 9.04. You can skip this step if you have already upgraded to Ubuntu 9.04.
Press Alt + F2 on your keyboard and type in
The Update Manager will appear. Click on the Upgrade button.
Depending on your Internet connection, the upgrade could last for several hours.
After you have downloaded the LiveCD, burn it into a CD or use the USB Startup Disk Creator (System -> Administration -> USB Startup Disk Creator) to create a bootable USB drive.
Once the system completes the upgrading, restart your computer and play around with it to make sure that it is working fine in your system.
When you are happy with the result, reboot the computer again, this time boot into your LiveCD.
Step 2: Upgrading to Ext4
Go to System->Partition Editor. This will show all the partition in your hard disk. Record down the filesystem ID of the partition that you want to convert to ext4.
Close the Partition Editor. Open a terminal, type the following:
sudo tune2fs -O extents,uninit_bg,dir_index /dev/XXXX
Replace XXXX by the filesystem ID that you have recorded just now.
Once that is done, type the following to fixed your partition:
sudo fsck -pf /dev/XXXX
Don’t forget to replace XXXX with your filesystem ID.
Mount your filesystem
sudo mount -t ext4 /dev/XXXX /mnt
Open the fstab file:
gksu gedit /mnt/etc/fstab
and change the ext3 entry to ext4. Save and exit.
Back to the terminal, we need to reinstall the grub bootloader.
sudo grub-install /dev/XXX
This time, replace the XXX by the filesystem without the number. For example, sudo grub-install /dev/sda
Close the terminal and restart the computer. Reboot into ubuntu 9.04.
In the terminal, type
You should see your filesystem mounted as ext4 now
That’s all. Enjoy!