[Simo Sorce]

On Tue, 2013-01-29 at 10:07 -0500, Stephen Gallagher wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On Tue 29 Jan 2013 09:45:34 AM EST, Jaroslav Reznik wrote:
> > = Features/DracutHostOnly =
> > https://fedoraproject.org/wiki/Features/DracutHostOnly
> >
> > Feature owner(s): Harald Hoyer <harald at redhat.com>
> >
> > Only create "host-only" initramfs images. A generic fallback image should be
> > installed by anaconda on installation/update and never ever be removed.
> >
> > == Detailed description ==
> > Current initramfs images contain most of the kernel drivers to boot from any
> > hardware. This results in a very big initramfs, which takes a long time to
> > load on system start and a long time to create on kernel updates. Switching to
> > host-only will improve the situation. To cope with hardware change, a boot
> > entry "Rescue System" should be installed with a full fledged initramfs also
> > containing debug tools. This boot entry can then be used to recover from
> > hardware changes and also from unforseen software failure after updates.
> 
> 
> This makes me nervous. Can we get some details on what comprises a
> "hardware change" necessitating that the user use the Rescue System
> mode?
> 
> - From the Feature page:
> This Fedora release ships with an initramfs tailored especially for
> your computer hardware. If you change your machine or significant
> hardware, you might have to boot with the "Rescue System" boot entry
> and execute "dracut --regenerate-all". If you want your initramfs to be
> hardware independent, execute "ln -s /dev/null
> /etc/dracut.conf.d/01-hostonly.conf".
> 
> 
> Can we do anything to detect such hardware changes and run the
> regeneration automatically? I'm wary of making changes that may result
> in unbootable systems if someone doesn't remember to plug their
> external hard drive in, for example.
> 
> Frankly, I'm not sure the faster boot is necessarily worth the
> increased likelihood of boot failure. I think I might prefer that this
> be available-but-not-default. Please convince me :)


Wow this brings me back to Windows 95/XP antifeatures where changing
hardware even a little bit strands you to not be able to boot and having
to go to rescue mode.

This is really a step back and is really bad to do it by default IMO.

Why are we doing this ?
Is this just to boot a little bit faster ?

Certainly generating the ramfs is not a big deal, it is done rarely
anyway. And every time you need to remove a kernel you have to
regenerate the full rescue system anyway, so every now and again you'll
need to do this.

I rebuilding is an issue, wouldn't it make sense to pre-generate the
rescue initramfs at kernel build time ? Does it really need to be
regenerated at install time ?


So in summary, can we rather keep the current behavior by default and
give the option to boot faster only to people that are interested in
it ?

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York