compiling kernel on remote...

j0hnd0e · 10-09-2006, 02:18 PM

Hi

First of all, sorry if this question was asked before, but I can't find an answer for it.

I need to compile new kernel on remote machine, but I wan't to be sure it will boot.
Well I have compiled it once, and restarted the machine, but the Kernel was freezed on start, and I must do reboot manually.

So is there anyway, to get machine boots new kernel and in case something goes wrong it will do booting old stable kernel?! Silly question maybe, but I think it should be some solution for it.

On remote machine is Debian running on 2.4.32 and LILO.

thanks in advance

John

kaz2100 · 10-09-2006, 02:29 PM

Hi,

How can panic-ed kernel know that kernel itself is in panic?

/bin/bash · 10-12-2006, 09:01 PM

Put this in image section for new kernel in lilo.conf
append="panic=15"
Then add a fallback=<command line>
fallback="Linux-old"

So it would look something like this:

Code:

image = /boot/vmlinuz
  root = /dev/hda5
  label = Linux
  initrd = /boot/initrd
  append="panic=15 reboot=warm"
  read-only
  fallback="Linux-old"
image = /boot/vmlinuz.old
  root = /dev/hda5
  label = Linux-old
  append="panic=15 reboot=warm"
  initrd = /boot/initrd.old
  read-only

NOTE: I have never tried this but it is documented in man lilo.conf

<edit> Yeah, it seems to work OK but you need to put this in a startup script somewhere:
lilo -R
That removes the fallback entry if you boot successfully. You could put it in /etc/rc.d/rc.local. If you don't have that line then every other time you boot you'll automatically boot into the fallback kernel.