Slow boot/login — how do I figure out the cause?

Question

My boot and login are a lot slower than a fresh install.

How do I trace the boot and login processes to figure out what programs are taking a long time to load?

Answer 1

One way is to use the bootchart package - this produces a .png image file showing what processes are being started and how long these processes run for. It also describes disk-throughput which shows how efficient information is fetched from your disk.

To install -

sudo apt-get install bootchart pybootchartgui

Reboot and login.

Look in /var/log/bootchart for the image file.

for example - part of my bootchart looks like:

To uninstall -

sudo apt-get remove bootchart pybootchartgui

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Possible causes of a slow boot

First check if you are running any unnecessary processes - for example bluetooth, modemmanager. Also check what processes are running after login.

Its also worth re-caching your ureadahead cache files - these files are used to speed up your boot. Remember, remove bootchart first, reboot, remove the *.pack files and reboot twice again before reinstalling bootchart.