Fedora tested in c't: grub missing feature

[Jeff Spaleta]

On Sun, Feb 8, 2009 at 11:11 AM, Jud Craft <craftjml at gmail.com> wrote:
> Don't get me wrong, I think they should definitely fix it (the
> kernel-update-path problem), but the kernel-update-path problem is
> causing difficulties for other distributions who install over Fedora,
> not for Fedora installing over someone else.  It's a separate problem.
>
> Unless all distributions do the tons-of-different-kernel-updates in
> GRUB thing.  I thought Fedora was the only one that did that.


When Fedora updates a kernel.. a new grub entry is added for the new
kernel and that grub entry is set to be the default. Older kernel
entries are automatically removed so that you have only 2 kernel
entries at a time. A current and a fallback. This is the default
configuration which can be tweaked with some config setting changes.

Now at install time of another linux operating system...they might be
able to capture the current state of your existing Fedora install by
gobbling up the grub entries. But once you have installed two update
kernels for that Fedora install...the boot loader from the other linux
install will no longer point to valid Fedora kernel images. If the
other linux installs its own seperate boot loader instance with
seperate configs...and only imports the Fedora boot loader configs at
OS install time... this will eventually break and the Fedora system
will not boot.  The other linux system installed after installing
Fedora will have to constantly monitor for changes in Fedora's
bootloader as Fedora's kernel is updated.

In fact this is an unsolvable situation. Any time the linux operating
systems are not sharing a common grub config, operates which modify
the grub config while booted into a linux system...like updating the
kernel unless will cause the other grub config to become out of sync
as long as the kernel images are versioned. Fedora provides a symlink
that always points to the current kernel and initrd images as
configured in its own boot configuration like thorsten has described.
Even then its not perfect because there is no way to statically inform
another bootloader of the cmdline options that might be new with a new
update kernel...but thats a corner case.

Ubuntu and OpenSuse need to stop doing what they are doing and
blacklist Fedora. What they are doing guarantees that Fedora will be
unbootable from their bootloader once the Fedora system has seen 2+
kernel updates.

-jef