Bootchart

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Bootchart is a handy tool used for profiling the Linux boot sequence, generally used for making your computer boot faster. It consists of the bootchartd daemon, which records and renders a chart of profiling data.

Installing Bootchart

Bootchart is currently unsupported, but available in the AUR with the most popular entry being this one.

Note: An alternative to Bootchart is bootchart2, which at least has more recent activity than 2005. It can be found on the AUR as bootchart2-gitAUR. It uses python for generating the final chart instead of a JVM, and only requires: pygtk, git and busibox. See GRUB and GRUB2 configuration bellow

Running Bootchart2

Boot loader setup

This generally involves making a copy of the boot option you want to profile and adding initcall_debug printk.time=y init=/sbin/bootchartd to it. When started from the boot loader, bootchart2 will stop after either a default 120 seconds, or when you get to the login prompt (as opposite.

Grub

Open up /boot/grub/menu.lst, and copy/paste the entry you want to log. Append initcall_debug printk.time=y quiet init=/sbin/bootchartd to the kernel line.

Lilo

TODO

Grub 2

Edit one of grub-mkconfig's custom files such as /etc/grub.d/40_custom (the parameters can also be added to the variable GRUB_CMDLINE_LINUX_DEFAULT in /etc/defaults/grub), or create a new file, copy the boot option you want to profile from /boot/grub/grub.cfg, and add bootchartd as follows:

menuentry "Arch Linux with Bootchart2" {
set root=(hd0,1)
linux /boot/vmlinuz-linux root=/dev/sda1 ro initcall_debug printk.time=y quiet init=/sbin/bootchartd
initrd /boot/initramfs-linux.img
}

Once this is done, generate a new grub.cfg:

# grub-mkconfig -o /boot/grub/grub.cfg

Now you can reboot and choose the new bootcharting option.

Configure Bootchart2

Stop Bootchartd2 after login

Bootchart2 /etc/bootchartd.conf

EXIT_PROC="kdm_greet xterm konsole gnome-terminal metacity mutter compiz ldm icewm-session enlightenment"

can be adjusted, or left empty for logging to be stopped manually rather than at a predetermined programme start.

Generating a chart

Is as straightforward with Bootchart2 as it is with Bootchart Legacy: After bootup, run

$ pybootchartgui -i 

to get an interactive chart rendering tool. You can get more details on the Gentoo Wiki until someone further edit this page.

Note that Bootchart2 can be used along with E4rat.

Running Bootchart

To make use of bootchart, you have to either set it as the init process in your boot loader or starting it manually from one of the init scripts (rc.sysinit preferably). Note that if you start bootchartd manually, you have to stop it manually too. In general, be extra careful with this step.

Boot loader setup

This generally involves making a copy of the boot option you want to profile and adding init=/usr/bin/bootchartd to it. When started from the boot loader, bootchart will stop when you get to the login prompt.

Grub

Open up /boot/grub/menu.lst, and copy/paste the entry you want to log. Append init=/usr/bin/bootchartd to the kernel line. Example:

# (1) Arch Linux Bootchart
title  Arch Linux
root   (hd0,0)
kernel /vmlinuz-linux root=/dev/disk/by-uuid/d531ff5b-de65-499a-9942-d18682375163 ro quiet init=/usr/bin/bootchartd
initrd /initramfs-linux.img

Lilo

TODO

Grub 2

Edit one of grub-mkconfig's custom files such as /etc/grub.d/40_custom or create a new file, copy the boot option you want to profile from /boot/grub/grub.cfg, and add bootchartd as follows:

menuentry "Arch Linux with Bootchart" {
set root=(hd0,1)
linux /boot/vmlinuz-linux root=/dev/sda1 ro quiet init=/usr/bin/bootchartd
initrd /boot/initramfs-linux.img
}

Once this is done, generate a new grub.cfg:

# grub-mkconfig -o /boot/grub/grub.cfg

Now you can reboot and choose the new bootcharting option.

rc.sysinit setup

This one is dangerous (you can make your Arch Linux unbootable) - use it only when the first approach fails. When run in this way, not only you'll have to stop bootchartd manually after you boot up (or it will completely fill your harddrive) but it will start with every boot too. Also, any changes to /etc/rc.sysinit will be reverted next time you update the initscripts package. On the positive side, you'll end up with a bootchart that shows what happens after you log in.

Edit /etc/rc.sysinit

Now, we're going to add this line:

/usr/bin/bootchartd start

to /etc/rc.sysinit

It cannot be too high up, because that would render the system unbootable, but placing it too far into the script will hide anything that happened before from the bootchart. It should be safe to put this right before the section that brings up the system clock. Look for this line:

stat_busy "Configuring System Clock"

Put this:

/usr/bin/bootchartd start

before it.

Stop bootchartd after login

As stated previously, you have to stop bootchartd manually. Either run this as root:

/usr/bin/bootchartd stop

Or with sudo if you have that set up:

sudo /usr/bin/bootchartd stop

Generating a chart

Generating a bootchart involves running:

bootchart-render

in a folder to which you have write access. This will generate a bootchart.png image with your chart. You'll have to have a Java runtime installed and properly set up before you can do this.

Troubleshooting

Bootchart-render cannot generate a 'bootchart.png' image and shows the error message:

/var/log/bootchart.tgz not found

It mostly means that bootchartd was unable to detect when the booting process was finished. This can happen when you are using different login manager than KDM or GDM such as SLIM or entrance. You have to open /usr/bin/bootchartd script and append those applications to exit_proc variable, for example:

# The processes we have to wait for
local exit_proc="gdmgreeter gdm-binary kdm_greet kdm slim"

If you are using no login manager, edit the exit_proc variable in this way:

# The processes we have to wait for
local exit_proc="login"

Example bootcharts

Boot in 5 seconds

LWN Article on fast booting netbooks

This article is really awesome and along with a bunch of bootcharts provides some tips on how to boot faster. Some of those improvements are beyond reach of the ordinary user though (patching X.org, kernel, etc.).

Useful links