Bootchart is a tool used to analyze your system performance in linux boot process. It process all the required information accumulated during the boot process (CPU usage and disk usage) which will then display as PNG, SVG, EPS encoded chart.
First of all you will have to Install Bootchart on Ubuntu.
To active or install Bootchart you will have to open command console
sudo aptitude install bootchart
When you restart your computer Bootchart will create a graphical illustration in .png format.
Disabling and Enabling Bootchart
To disable Bootchart just use these code
sudo update-rc.d -f stop-bootchart remove
Removing any system startup links for /etc/init.d/stop-bootchart ...
And to re-enable just use these codes
sudo update-rc.d stop-bootchart start 99 2 3 4 5 .
Adding system startup for /etc/init.d/stop-bootchart ...
/etc/rc2.d/S99stop-bootchart -> ../init.d/stop-bootchart
/etc/rc3.d/S99stop-bootchart -> ../init.d/stop-bootchart
/etc/rc4.d/S99stop-bootchart -> ../init.d/stop-bootchart
/etc/rc5.d/S99stop-bootchart -> ../init.d/stop-bootchart