Bootchart is a tool for performance analysis and visualization of the GNU/Linux boot process. Resource utilization data and process information are collected during the boot process, and can later be displayed in a PNG, SVG, or EPS encoded chart. Analyzing the chart will help in finding opportunities for optimization.
The first thing we must do is, obviously, install the package, open yast -- software managment and search for "bootchart" and click on "Accept" to install bootchart
Bootchart provides a shell script to be run by the kernel in the init phase. The script will run in background and collect process information, CPU statistics and disk usage statistics from the /proc file system. The performance data are stored in memory and are written to disk once the boot process completes.
The boot log file is later processed using a Java application (or the web form) which builds the process tree and renders a performance chart in different formats.
Bootchartd mounts a tmpfs below /tmp, so make sure you don't clear this at boot time, otherwise you will have invalid data.
Especially check the setting of: CLEAR_TMP_DIRS_AT_BOOTUP in sysconfig/cron
Reboot your system and after reboot you will find two files (bootchart.tgz and bootchart.png) under /var/log directory and this png file will give you detail view of the time that a particular process has taken while booting so that you can look into it and can optimize it for faster booting.