F8 kernel-2.6.24.3-12.fc8

[Zing]

On Mon, 10 Mar 2008 14:23:53 -0500, Callum Lerwick wrote:

> On Mon, 2008-03-10 at 01:22 -0700, Andrew Farris wrote:
>> In any case, the try-catch mechanism is in place by keeping the prior
>> kernel installed, and if it fails you choose the next one in the list
>> next time.  It is not possible to try a kernel until its been booted,
>> and when it does boot if the kernel itself misbehaves it is not
>> possible to do anything automatic because the kernel has failed to do
>> what it should do...
> 
> It's easy. It's much like the dirty flag on filesystems. GRUB writes a
> flag somewhere on disk, that indicates "Attempting to boot kernel
> 2.6.XXXXX". Then somewhere in the early userspace init scripts, you
> change the flag to "Finished booting kernel 2.6.XXXX". The next time
> grub starts up, it sees this flag and it now knows that that particular
> kernel at least made it to userspace, which is a pretty good indication
> it's not completely b0rked. If GRUB starts up and sees a "Attempting
> boot" flag still remaining, then that's an indication that that kernel
> failed to boot.
> 
> And I know this idea has come up before... Is this on anyone's to-do
> list?

I believe redhat has been carrying around a patch in grub which 
essentially would allow the above, called "bootonce" patch.  It allows 
you to couple it with "reboot on kernel panic" and "failback" to a known 
working kernel... I've never tried it or had the use for it myself.