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-   -   Is it possible to slow down the kernel boot process ? (https://www.linuxquestions.org/questions/linux-general-1/is-it-possible-to-slow-down-the-kernel-boot-process-838040/)

Mike Davies 10-14-2010 09:40 AM

Is it possible to slow down the kernel boot process ?
 
I'm trying to upgrad from kernel 2.6.32.9 to 2.6.34.3 and I'm having problems.

The boot finished with that old gem "Kernel panic - not syncing: Attempting to kill init !"

I suspect that it's something to do with my PATA IDE driver because there have been kernel changes in this area.

My problem is all the boot messages scroll off the top of the screen before I can read them and it's no use saying look at dmesg or /var/log/messages because the root fs isn't there - another reason why I think it's to do with the drivers.

So my question is, is there some way I can slow down the boot process so that I have a chance of reading the messages ?

Tried Ctrl-S/Ctrl-Q and it doesn't work.

thanks

GrapefruiTgirl 10-14-2010 09:46 AM

You can also try the SCROLL-LOCK key to pause the boot messages; it works up until the framebuffer/console switches modes at which time the stuff on the screen is gone.

While paused by this method, SHIFT+PageUP and SHIFT+PageDn will scroll up/down.

Mike Davies 10-14-2010 09:56 AM

Scroll Lock does not work, but the Pause/Break button does cause a pause during the BIOS boot phase, but not while the kernel is spewing out it's messages.

Mike Davies 10-14-2010 10:05 AM

OK. Found a solution.

added following lines as boot parameters

console=ttyS0,9600n8 earlyprintk=serial,ttyS0,9600,keep

then watched on another computer

bbobbo 02-08-2011 03:10 PM

a couple of months old, but may be useful for someone looking for a solution that doesn't involve a serial cable and another computer.

Quote:

Slowing down the speed of text output with boot_delay=1000 (the number may need to be tweaked higher/lower to suit) may allow the user to take a digital camera photo of the last thing on screen.
from: http://fedoraproject.org/wiki/KernelCommonProblems

"boot_delay=1000" should be added to the kernel options in grub.conf

1000 may be interminably slow--might be best to start off with a much smaller delay and slowly increase the values if necessary.


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