[arch-general] Reboot - Versioned Kernel Installs

[Yaro Kasear]

On Thursday, June 09, 2011 21:22:50 Timothy L. wrote:
> On Thu, Jun 9, 2011 at 9:25 PM, C Anthony Risinger <anthony at xtfx.me> wrote:
> > On Jun 9, 2011 5:50 PM, "Heiko Baums" <lists at baums-on-web.de> wrote:
> > > Am Thu, 9 Jun 2011 17:36:21 -0500
> > > 
> > > schrieb C Anthony Risinger <anthony at xtfx.me>:
> > >> does this sound genius or completely insane? some insanely genius guy
> > >> once said they are only separated by a fine line ...
> > > 
> > > Sounds completely insane.
> > 
> > ooooook ... and ... why?
> > 
> > ) initramfs is not very big (fallback on my sys is only 13MB + 2MB kern)
> > ) keeps the whole thing in mkinitcpio
> > ) does not affect any current images and is even backward compat
> > ) small chance of absolute failure (i think :-)
> > ) only small changes to mkinitcpio, if any at all
> > ) ...
> > ) ... KISS BABY!
> > ) oh yeah and ... PROFIT!
> > 
> > im pretty sure it could be implemented as a hook (possibly 2) to the
> > current system ... this might even be the best way.  `install` hook
> > would unpack the current image to a known location (prob
> > `/lib/initcpio` somewhere), copy the kernel to the same place, and
> > then add the directory to the image (after removing the old-old image
> > if existed :-).  the real `hook` would then check for one of two
> > flags:
> > 
> > ) kexec.flag ... kexec the old kernel with the boot.flag
> > ) boot.flag ... chroot to "previous", run old hooks/mods/etc, exit
> > chroot, switch_root like normal
> > 
> > i thought it was pretty succinct ... elegant even :-)  ... with some
> > sprinkles of insanity that give it the funny but mildly enjoyable
> > aftertaste.  i don't have any free time for a couple days, but i'm
> > *pretty* sure this could be done as a hook to the current mkinitcpio
> > in a couple hours -- might take a whack at it this weekend, would be
> > useful, as i've personally mucked my boot more than once, and though i
> > can recover easily enough, i'm liking this more and more ...
> > 
> > ... though i could very well be missing something obvious, certainly
> > wouldn't be the first time ... surely someone out there reads this and
> > thinks "why not?"
> > 
> > C Anthony
> 
> Keeping the previous kernel after upgrading sounds sane to me. For the
> apprehensive, couldn't we just include a simple configuration option/check
> somewhere?
> 
> /etc/mkinitcpio.conf
> KEEP_PREVIOUS_KERNEL="yes"
> 
> I've read most of this thread but please excuse me if this has already been
> mentioned.

I'd accept that solution just so long as the default is set to "no" and not 
"yes." Most Arch people don't want old kernels.