How to Pause the screen during boot process?

If you can use your computer and log in, go to System->Administration->System Log. Your message should be under kern.log somewhere at the beginning. Also, searching the web for what you have sniffed, I ended upon this thread: http://www.ale.org/archive/ale/ale-2002-09/msg00638.html. Maybe it will help you in your further investigation.

Ok, thanks for the response. I checked under Sys Log under kern.log but found nothing.
I checked out your link. It happened to this guy back in 2002 and i read thru most of the Threads on it from folks using the ALE system [Atlanta Linux Enthusiasts] . I'll quote some of it so maybe it will ring a bell with some folks now:
///
"Re: [ale] Strange kernel message

    * To: Matthew Brown <email address hidden>
    * Subject: Re: [ale] Strange kernel message
    * From: Tom Wiencko <email address hidden>
    * Date: Sat, 21 Sep 2002 17:31:19 +0000
    * CC: "'Atlanta Linux User Group (E-mail)'" <email address hidden>
    * Delivered-To: mailing list <email address hidden>
    * list-help: <mailto:<email address hidden>>
    * list-post: <mailto:<email address hidden>>
    * list-unsubscribe: <mailto:<email address hidden>>
    * Mailing-List: contact <email address hidden>; run by ezmlm
    * Organization: Wiencko & Associates, Inc.
    * References: <002c01c260d0$3b8dfba0$af00a8c0@mab1>
    * Sender: tew2

///
A little computer trivia/history from the old guy here...

NMI is the signal line into a CPU which causes a "Non-Maskable
Interrupt." What that means is that there are a variety of ways that
an external device can get the attention of the CPU, typically by
asserting a given signal line called an "interrupt." This causes
the CPU to stop what it is doing and execute a special routine, called
an "interrupt service routine" to see what the device needs to have
done.

While an interrupt service routine (ISR) is executing, the rest of the
interrupt process is turned off until the routine releases other
interrupts to be recognized (because it causes all sorts of problems
for ISRs to themselves be interrupted). This is "disabling"
interrupts. There are also mechanisms that allow certain groups of
interrupts to be temporarily disabled (for similar reasons). This is
called "masking" interrupts.

There is one interrupt that cannot be masked or disabled, typically
because it will be used to handle very, very high priority external
events (like power failure). This interrupt line is called
"Non-Maskable" and its usual label on the chip itself is "NMI" for
Non-Maskable Interrupt. It can actually be used for anything (including
"wake-on-LAN") but its use is typically restricted to unusual events
that circumvent normal processor interrupt handling.

Tom

Matthew Brown wrote:
>
> Isn't NMI "Network Management Interface"? I thought this was doing a
> Wake-On-Network type of thing for rebooting, etc. from a network
> management interface. Maybe I'm WAAAAAY off here.
>
--
------------------------------------------------------------------------
Tom Wiencko <email address hidden>
President - Wiencko & Associates, Inc. (404) 255-2330
Telecom Consulting & Project Development -- Wireline, Wireless, Internet

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And i still need to know how to pause or freeze the screen while it is booting up [?]

Will ctrl-S (pause) and ctrl-Q (resume) work?
Once booted you can also use dmesg.

ok, i'll try that.
I went back one day in the log and found the lines. I included the one preceding and the one after:

Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.858338] SMP motherboard not detected.
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.862367] Uhhuh. NMI received for unknown reason 3d on CPU 0.

Jul8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.862422] Do you have a strange power saving mode enabled?
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.862473] Dazed and confused, but trying to continue
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.964490] Brought up 1 CPUs
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.964985] Booting paravirtualized kernel on bare hardware

Press the 'Pause' key (maybe called Break key)

No, the "scroll Lock" and the "Pause Break" keys don't work. I have yet to try CTRL+S and CTRL+Q, which i'll try next time i reboot.

I tried thje ctrl+S and it didnt work either. Any other ways to freeze or pause the screen while booting?

Can you just log through /var/log/dmesg ?

that will show everything from time of boot till the run level is initiated.

I need a clarification of that last comment: how do i "log through /var/log/dmesg"?
Do i type that in the terminal? If so, i tried it and it said "permission denied".

As I told you above, the command is simply dmesg.

Hi again,

If your question is "how can I see what was written at boot time" then you've found your answer:

Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.858338] SMP motherboard not detected.
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.862367] Uhhuh. NMI received for unknown reason 3d on CPU 0.

Jul8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.862422] Do you have a strange power saving mode enabled?
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.862473] Dazed and confused, but trying to continue
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.964490] Brought up 1 CPUs
Jul 8 01:02:54 c-67-168-216-16-Pirate kernel: [ 20.964985] Booting paravirtualized kernel on bare

If you truly want to pause the boot process, try Cesare's solution with CTRL+S and CTRL+Q.

My suggestion is to search the web for you error messages and see if you find anything usefull.

Ok, so there is no way to stop or pause the screen while it's booting up? Ok, then i'll quit this.
Yes, when i use "dmesg" i get everything that was flashed on the screen during boot-up.
Ok, it's 5 am here and i must crash - - oops! i mean go to sleep. Thanks for your help.

to the original poster

sudo less /var/log/dmesg

or

sudo cat /var/log/dmesg > ~/dmesg.log (and go through it with gedit )

Thanks Cesare Tirabassi, that solved my question.