[CentOS] building a new kernel, problems booting without initrd

[Peter van Eck]

Just for your info.

Gentoo is a linux from scratch type of distro.

You build/compile the system to your own needs which obviously involves
building a custom kernel from for instance the vanilla-sources at
kernel.org.

rgds,

Peter

Richard Hubbell wrote:

>Thanks Jim.
>I have a need, but if it won't work, it won't work.  I may switch distribs
>if CentOS kernel is inextricably intertwined with the rest of the bits.
>
>FWIW I don't need/want selinux and can get by without nptl if it
>proves troublesome. The kernel also has way too much stuff in
>it that I don't need, etc., etc.
>
>The link you mention is broken.
>Dunno what gentoo's about so no comment there.
>
>
>On 12/11/05, Jim Perrin <jperrin at gmail.com> wrote:
>  
>
>>On 12/11/05, Richard Hubbell <richard.hubbell at gmail.com> wrote:
>>    
>>
>>>Hello all,
>>>
>>>Grabbed a new kernel (from kernel.org) to build a custom kernel
>>>but it won't boot.  I followed the directions at redhat to setup a box without
>>>initrd (which I don't want and don't need to use). But the system hangs.
>>>Has anyone built a custom kernel without using initrd? I'm using CentOS 4.2.
>>>It hangs at or after "Freeing unused memory"
>>>
>>>Thanks.
>>>
>>>excerpt from the page:
>>>(http://fedora.redhat.com/docs/udev/)
>>>
>>>Udev without initrd
>>>
>>>Install Fedore Core as usual and reboot. Execute the following commands
>>>
>>>
>>>mkdir /tmp/dev
>>>mount --move /dev /tmp/dev
>>>sbin/MAKEDEV null console zero
>>>mount --move /tmp/dev /dev
>>>
>>>Install your kernel without an initrd. Reboot.
>>>
>>>You will get some SELinux errors, and syslogd will not work as expected.
>>>      
>>>
>>Why is it that you feel the need to rebuild the kernel?
>>
>>The centos/rhel system is built atop a very heavily patched kernel. If
>>you build from straight vanilla source from kernel.org, expect
>>breakage. There are things like selinux, nptl, etc that will break for
>>you, and may or may not cause apps to fail or behave erratically, the
>>system to hang (seems like you found that one already) etc.
>>
>>basically, if you need to rebuild the kernel, you should do so from
>>within the most recent kernel source rpm. Anything else is going to
>>cause issues, and you're likely to be on your own for help.
>>
>>All that negativity aside, there's a tutorial on how to rebuild
>>kernels via source rpm here:
>>crab-lab.zool.ohiou.edu/kevin/kernel-compilation-tutorial-en/
>>
>>Please. centos isn't gentoo and I'd advice not treating it as such if
>>it's possible. If what you need isn't in the stock kernel, then look
>>to the centosplus kernel. If it's not there, ask on the mailing list
>>or on irc. Others may need what you're after if you have a valid
>>reason.
>>
>>
>>--
>>Jim Perrin
>>System Architect - UIT
>>Ft Gordon & US Army Signal Center
>>_______________________________________________
>>CentOS mailing list
>>CentOS at centos.org
>>http://lists.centos.org/mailman/listinfo/centos
>>
>>    
>>
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