[gentoo-user] Kernel upgrade problem

[David Relson]

G'day,

Due to problems experienced with 2.6.25-gentoo-r7, I've built
2.6.27-gentoo-r2. I started with the 2.6.25-r7 .config file, ran
"make oldconfig", then "genkernel all". The new 2.6.27 kernel appears
to load modules OK, then hangs. The old 2.6.25-r7 kernel displays
"Activating mdev" after it finishes loading modules.

Any suggestions of what to check for or change?

Thanks.

David

[Dirk Heinrichs]

Am Dienstag, 4. November 2008 20:51:10 schrieb David Relson:

> Due to problems experienced with 2.6.25-gentoo-r7, I've built
> 2.6.27-gentoo-r2. I started with the 2.6.25-r7 .config file, ran
> "make oldconfig", then "genkernel all".

Don't know if that helps, but anyway, here's what I usually do:

I only use kernel.org kernels (vanilla-sources in Gentoo). They're the same no
matter the distro.

I have a copy of my kernel config (in /etc/kernel/config). If you configured
your kernel appropriately, you can also find the config of the running kernel
in /proc/config(.gz). Upon a major kernel upgrade, I run make menuconfig, load
my old config file and check all the important options, eventually switching
on/off new options which I find useful.

I never ever ran make oldconfig. I also never ran genkernel. Why should I?
After leaving menuconfig it's just make, make modules_install, make install
(or copy the appropriate kernel file to /boot manually).

Then I run a self-written script which updates some symlinks in /boot (so that
I don't need to edit grub.conf) and cleans /lib/modules, leaving only the
currently running kernel and the new one arround, together with their modules.

I didn't have a kernel related boot problem since a very long time now. But
even if I had, I still have the old one.

> The new 2.6.27 kernel appears
> to load modules OK, then hangs. The old 2.6.25-r7 kernel displays
> "Activating mdev" after it finishes loading modules.

Don't know what mdev is (or is this a typo: udev), so I can't help with this.

> Any suggestions of what to check for or change?

Try to diff both kernel configs. Look wether there's something missing in the
new one that was there in the old. Maybe try again with the method described
above.

BTW: I'm running 2.6.27.4 w/o any problem.

Bye...

Dirk

[David Relson]

Hello Dirk,

Thanks for taking the time to reply. The combination of gentoo-sources
and genkernel has been working quite well for the 2 yrs I've been
running Gentoo. It's convenient to have grub.conf auto-magically
updated and that's not been an issue.

When upgrading from one kernel revision to another, oldconfig is nice
because it makes the new kernel options obvious. Using menuconfig
hides that information. Of course, as you point out, diff can be used
after either tool to see exactly what has been changed.

The messages I mentioned, i.e. "Loading modules" and "Activating mdev"
appear during the boot process before /etc/init.d scripts are run (and,
yes, it's "mdev", not "udev"). However, I don't know which program is
running and printing these messages.

'Tis good to hear that 2.6.27.4 is working for you. However my hardware
(AMD64x2, IDE drive, etc) and kernel options are, I wager, different
than yours and _something_ in 2.6.27 is unhappy. The question of the
day is "What?".

Regards,

David

[Jorge Peixoto de Morais Neto]

On Tue, Nov 4, 2008 at 8:56 PM, David Relson <rel...@osagesoftware.com> wrote:
> Hello Dirk,
>
> Thanks for taking the time to reply. The combination of gentoo-sources
> and genkernel has been working quite well for the 2 yrs I've been
> running Gentoo. It's convenient to have grub.conf auto-magically
> updated and that's not been an issue.

You don't need to edit grub.conf at all.
"make install" automatically updates the symlinks in /boot/
For me, the kernel update process is:
emerge -a1v sys-kernel/vanilla-sources
cd /usr/src/linux
// I usually issue make defconfig to start with a fresh config. But if
you skip make defconfig, the following command will start with your
old config from /boot/config
make menuconfig
make
make install modules_install
//The above command automatically copies the kernel image, System.map
and .config to /boot and updates the /boot/vmlinuz, /boot/vmlinuz.old,
/boot/config, /boot/config.old, /boot/System.map, /boot/System.map.old
symlinks. It also copies the modules to /lib/modules
//No need for genkernel, no need to edit grub.conf
*reboot
*delete obsolete modules in /lib/modules, and obsolete files in /boot
*By the way, before i delete obsolete config file in /boot, i back it
up in a oldconfigs.tar.lzma compressed archive.