[CentOS] Request for good advice to upgrade kernel

[Ralph Angenendt]

Kari Salovaara wrote:
> But I've lost some understanding how these kernel versions flow !  I'm 
> also a little confused of some related answers from some forums and 
> lists. Questions :
> - is the kernel version used in CentOS the same as in kernel.org ?

Yes, the CentOS 2.6.9 *base* kernel (which is the kernel 4.0 shipped
with) is pretty close to the 2.6.9 kernel from kernel.org plus some
patches (I don't know how many there were, though).

kernel 2.6.9-34.EL still is based on kernel.org's 2.6.9 kernel, but has at
least 700 patches in it (that is added up for all architectures, so your
i386 kernel doesn't really have 700 patches applied to it). But the
kernel-API is still the same as in 2.6.9 (later 2.6.x kernels have a
different one).

> - if the kernel versions don't match, where do I get information which 
> mathes which ?

The kernel-rpm comes with a pretty detailed changelog, so "rpm -q
--changelog kernel-2.6.9-34.EL |less" will tell you, what has been added
to the kernels since the first packaging of a 2.6.9 kernel for CentOS4.

That means: Security Fixes *and* updated or new drivers get backported
to the main kernel line in CentOS4/RHEL4 - which is kernel.org's kernel
2.6.9.

> The other question (very much relates to the later part of previous 
> question and the need to do kernel compilation at all) :
> - if I want to compile new kernel using kernel source from kernel.org, 
> what is the best way regarding to maintain the workability level of 
> exisisting kenel (see top)?

You leave the path of binary compatibility to RHEL4.

> -- can I use .config-file from working 2.6.9-34ELsmp source and compile 
> straight using that (first to see a working new kernel and then make 
> some adjustments) ? In this way I can save a lot of time and frustration 
> when setting the flags for compilation. Any other important to remember 
> ? (I've compiled kernel since Linux 0.6 so no newbee recommendations. ;-) )

The first question asked here is always: Why do you think you need to
recompile your kernel? The answer most often is: You don't need to - if
you want to compile in additional kernel modules, installing the
kernel-devel rpm is normally all it takes to be able to compile those
modules.

Regarding OpenIPMI:

kernel 2.6.9-34 seems to have some IPMI support built as modules, just
take a look at /boot/config-2.6.9-34.EL (or .ELsmp for the smp kernel).


Regards,

Ralph
-- 
Ralph Angenendt......ra at br-online.de | .."Text processing has made it possible
Bayerischer Rundfunk...80300 München | ....to right-justify any idea, even one
Programmbereich.Bayern 3, Jugend und | .which cannot be justified on any other
Multimedia.........Tl:089.5900.16023 | ..........grounds." -- J. Finnegan, USC
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://lists.centos.org/pipermail/centos/attachments/20060321/c6a5c3ea/attachment.sig>