Logging Everything Displayed At Boot

Wayne Sallee · 07-13-2011, 01:54 PM

Is there a way to get Linux to log all of the output that you see on the screen at boot?

It would sure beat having to dig through all of the different log files trying to find what was seen while it was booting.

Wayne Sallee
Wayne@WayneSallee.com

MrCode · 07-13-2011, 01:57 PM

If you're looking for kernel messages (i.e. the stuff that you see literally right after the bootloader starts booting the system), try dmesg. You can pipe the output to head/tail to see messages from the beginning/end of the log respectively.

druuna · 07-13-2011, 01:58 PM

Hi,

The dmesg command can be used to do that.

If the bare command doesn't show all the message you can use the -s <number> option:

Code:

/bin/dmesg -s32768 > /var/log/boot.messages

You can add the above part to one of your boot scripts (you don't mention your distro, so I cannot be more specific).

Hope this helps.

repo · 07-13-2011, 01:59 PM

Depending on the distribution, edit

Code:

/etc/default/bootlogd

Code:

# Run bootlogd at startup ?
BOOTLOGD_ENABLE=Yes

Kind regards

EricTRA · 07-13-2011, 02:00 PM

Hello,

What distro and version are you using? Check if you have a file /etc/default/bootlogd (Debian based distro does). In that file change the setting

Code:

BOOTLOGD_ENABLE=No

to

Code:

BOOTLOGD_ENABLE=Yes

and on your next boot everything should be getting logged into /var/log/boot. Hope it helps.

Kind regards,

Eric

Wayne Sallee · 07-13-2011, 02:29 PM

Wow! that was some fast responses.

I'm using Mandriva.

I did find a file called "useradd" in /etc/default
It has some similar commands.

I did the /bin/dmesg > /var/log/boot.messages and it produced a file that contains the same thing that boot.log contains, but this is far from being everything that shows up on boot. I have not rebooted yet, so I don't know if it will contain more detail later.

Edit: contains the same thing as dmesg

Wayne Sallee
Wayne@WayneSallee.com

repo · 07-13-2011, 02:57 PM

Take a look in

Code:

/etc/sysconfig

if boot logging is enabled.
The boot log file(s) are located at /var/log/boot.log

Kind regards

Wayne Sallee · 07-13-2011, 03:28 PM

Quote:

Originally Posted by repo

Take a look in

Code:

/etc/sysconfig

Ok sysconfig is a folder,,,,,,,,,

Wayne Sallee
Wayne@WayneSallee.com

Wayne Sallee · 07-18-2011, 02:01 PM

Anyone know of a way to get Linux to log all of the output that you see on the screen at boot?

It would sure beat having to dig through all of the different log files trying to find what was seen while it was booting.

Wayne Sallee
Wayne@WayneSallee.com

EricTRA · 07-19-2011, 02:58 AM

Hi Wayne,

Can you check first if you have bootlogd installed by running:

Code:

which bootlogd

If you have it installed you should be able to configure it through /etc/sysconfig (I don't know Mandriva but there should be a file in that directory to configure bootlogd). Another option, if you have it installed, is indicated in this post.

Kind regards,

Eric

Wayne Sallee · 07-19-2011, 02:18 PM

Quote:

Originally Posted by EricTRA

Hello,

What distro and version are you using? Check if you have a file /etc/default/bootlogd (Debian based distro does). In that file change the setting

Code:

BOOTLOGD_ENABLE=No

to

Code:

BOOTLOGD_ENABLE=Yes

and on your next boot everything should be getting logged into /var/log/boot. Hope it helps.

Kind regards,

Eric

Ok in Mandriva the file is:
/etc/sysconfig/bootlogd
so change BOOTLOGD_ENABLE=No to:
BOOTLOGD_ENABLE=yes

But if you look at the man files for bootlogd:
http://www.tin.org/bin/man.cgi?section=8&topic=bootlogd
there are options availale,,, so,,,,
In Mandriva the sh file that runs bootlogd is:
/etc/init.d/bootlogd

In that file, I see the code:

Code:

BOOTLOGD_OPTS="-r -c"

Since Mandriva already does a log boot(though not all of it) to /var/log/boot.log I have changed the code to the following:

Code:

BOOTLOGD_OPTS="-r -c -l /var/log/full_boot_log"

to differentiate it from the normal boot.log that mandriva already makes.

Well, now that I've done that, I will restart, and hopefully it does not crash and burn. :-)

But then now I see that there is also a binary file /sbin/bootlogd

Wayne Sallee
Wayne@WayneSallee.com

Wayne Sallee · 07-19-2011, 02:42 PM

Well it did not crash an burn, but it accomplished absolutely nothing

Wayne Sallee
Wayne@WayneSallee.com

Wayne Sallee · 07-21-2011, 12:07 PM

I edited /etc/init.d/bootlogd again and changed

Code:

BOOTLOGD_OPTS="-r -c -l /var/log/full_boot_log"

back to

Code:

BOOTLOGD_OPTS="-r -c"

and added the following to the start of the code to see if it was running

Code:

echo "*******************************************************************************************
********************************************************************************************
***********************************************************************************************
Starting boot log ***********************"
echo "*******************************************************************************************
********************************************************************************************
***********************************************************************************************
Starting boot log ***********************"
echo "*******************************************************************************************
********************************************************************************************
***********************************************************************************************
Starting boot log ***********************"
echo "*******************************************************************************************
********************************************************************************************
***********************************************************************************************
Starting boot log ***********************"

but I never saw it on the boot.

Wayne Sallee
Wayne@WayneSallee.com

Wayne Sallee · 07-21-2011, 12:25 PM

So now I edited /etc/init.d/bootlogd
and changed

Code:

# Because bootlogd is broken on some systems, we take the special measure
# of requiring it to be enabled by setting an environment variable.

to

Code:

# Because bootlogd is broken on some systems, we take the special measure
# of requiring it to be enabled by setting an environment variable.

# that's crazy, just run and exit
./sbin/bootlogd & exit 0
# by

I'll see how that works. :-)

Wayne Sallee
Wayne@WayneSallee.com

Wayne Sallee · 07-21-2011, 12:35 PM

I still get nothing.

Wayne Sallee
Wayne@WayneSallee.com