[vox-tech] need to debug boot crash

[eric nelson]

Peter Jay Salzman wrote:

> remember that not every "error" is a real error.  for instance, a micro
> channel driver can search your system buses for a micro channel device
> and not find one.  it'll print something vaguely error-ish to screen.
>
> you didn't say if your kernel is panicking or not.
>
> assumming your kernel isn't panicked, you can do shift-pageup to scroll
> up on the console.
>

Its not panicking.  I'm doing an nfs mount of the os, and something went
wrong init the initscripts.  The shift-pageup is a really good idea, I didn't
know about that.  The problem is that so many errors spewed out that I
coulldn't get far enough back.

>
> you can also look in /var/log/messages or dmesg | less.
>
> note that most module related errors upon boot don't make it into the
> error log.  some kernel developers are working on that.  there's a good
> reason for it (but i can't recall).
>
> if your kernel is panicking, your options are a bit more limited.  the
> easiest way (assumming you're not henry house who knows how to do the
> serial console thing) is to take a picture of your monitor with a
> digital camera.  however, most kernel panics usually don't print tons of
> error messages for this exact reason.  if the problem is a root
> filesystem that can't be found or a bona-fide "oops", you'll see 2 or 3
> lines of error at most.
>
> note, a very, very, very, very worthwhile thing is to extend the buffer
> that your kernel allocates for the scrollback.  it's in the linux FAQ.
> basically, you need to recompile your kernel and define something like:
>
> #define VIDEOCARD_CAN_DO_32_MEGS

I will do this.  The picture thing is a good idea.  I was finally able to get
a handle on things by putting a call to bash in the first init script.  Now I
can look at the initialization, by putting the call to bash in different
places, and finding where it goes wrong.  Thanks. ;~)

>
>
> (this isn't it -- you'll have to look up the exact define).  i do it
> each time i compile a new kernel.  it gives you ALOT more scroll back
> buffer space.
>
> pete
>
> begin eric nelson <en77@pacbell.net>
> > I have an error occuring during boot.  However, the pertinant
> > information flys by, and I just get a long list of error messages on the
> > screen.  Is there a way to record the messages during the late part of
> > kernel boot, or to make it slow down, or require a prompt, or something?
> >
> > _______________________________________________
> > vox-tech mailing list
> > vox-tech@lists.lugod.org
> > http://lists.lugod.org/mailman/listinfo/vox-tech
> _______________________________________________
> vox-tech mailing list
> vox-tech@lists.lugod.org
> http://lists.lugod.org/mailman/listinfo/vox-tech