HOWTO: Log Boot Messages

[Sephiriz]

At times I find it very difficult to see what has succesfully loaded or not during boot up, and at those times I wish I could have a log to look over in calm. After inquiring, someone (namely Nequeo) discovered this logging functionality.

Here's how to set it up:

You need to enable boot logging by opening a terminal and typing the following:

$ sudo gedit /etc/default/bootlogd

The text editor will open, and the following will be show:

# Run bootlogd at startup ?
BOOTLOGD_ENABLE=No

Change BOOTLOGD_ENABLE to yes

Now, everytime you restart, /var/log/boot will be created, and it will contain a log of all your boot messages. You need to be root to open it, so you can easily open it up again with sudo.

All thanks go to Nequeo for figuring this out, he also added the following:

NOTE: On my machine, I get a message on my screen during boot saying that the boot log has failed. But it was lying, the boot log worked just fine.

ALSO NOTE: The boot log will be full of lines like this '^[[A^[[74G[ ok ]'. All that 'garbage' is just the color code used to display the text as white or red during boot. It seems to get captured along with all the rest of the text.

So there you have it! This is a really useful feature, and I was slightly surprised that this was disabled by default.

[renoir98]

This is a really useful feature, and I was slightly surprised that this was disabled by default.

Totally agreed!

[raphha]

Very helpful indeed, thank you Sephiriz
raph

[henriquemaia]

Very helpful! Thanks a lot.

[mlomker]

I was looking for this the other day and couldn't find it. I assumed that since it was running out of rcS.d that it must just be the kernel.log or something.

As I open a terminal to read through ALL of the files in /etc/default...

[Marcos.Rufino]

Totally agreed!

For Christ sake!! I've lost hours trying to figure out where I could read the boot log. I really don't know why the developers disabled this log. Thanks!

[Peepsalot]

Hmm, I tried this and rebooted, but I see no boot file in /var/log
Any ideas what is going on?

There is a bootstrap.log, but I don't think that is the same thing.

[jfdill_2]

bootlogd seems to be borked:

bootlogd: cannot find console device 136:0 in /dev

Trying this to start it up before udev:

update-rc.d -f bootlogd remove
update-rc.d bootlogd defaults 08

Update: Yeah, that fixed it for me.

[UeB]

Hallo!

i also want to use this usefull feature.
but after changing
BOOTLOGD_ENABLE=No
to
BOOTLOGD_ENABLE=yes
in /etc/default/bootlogd

and rebooting twice still no file nameed "boot" exists in /vat/log or anywhere on the hard disk (after serching for "boot")

anybody have an idea why?
thanks!

PS i use the dapper version of ubuntu i dont know if this makes a difference...

[Cariboo1938]

Hmm, I tried this and rebooted, but I see no boot file in /var/log
Any ideas what is going on?
There is a bootstrap.log, but I don't think that is the same thing.

I have the same problem....I can't find a "boot"file in /var/log either, actually nowhere on the HDD!
Can anybody help us to find it?