Ubuntu – How to improve the boot time? (bootchart and dmesg output included)


I've noticed that my boot time lately has been unusually slow. I am running 12.04 a laptop with a 2.40GHz CPU and 4GB of RAM. I've run bootchart and dmesg, but I'm not sure how to use them to address the issue.

Here's the bootchart:


Here's the dmesg output (it was too long to paste here): http://pastebin.com/bspNtsux.

Any help would be much appreciated. Let me know if I can provide any more information. Thanks in advance.

Best Answer

I don't know what boot time you are expecting, and how long it used to take on this machine. I think the ureadahead part is quite long, but I'm not sure, as I use SSDs for years now...

Anyway, you can have a look at the post http://ubuntuforums.org/showthread.php?t=1434502 which explains ureadahead.

From this post, you can try the following:

  • trigger ureadahead reprofile

    sudo rm /var/lib/ureadahead/*.pack

    then reboot once to reprofile, and once again to see the result.

  • remove ureadahead and see if things get better (they will most probably get worse, but who knows ?)

    sudo mv /etc/init/ureadahead.conf /etc/init/ureadahead.disable

    then reboot and see if things are better. To reactivate ureadhead, rename /etc/init/ureadahead.disable back to /etc/init/ureadahead.conf

Does it help ?