Kernel upgrades using Redhat

[thor420]

Howdy folks,

This is somewhat of a general question. I recently upgraded to 2.4.10 (for good reasons) on my Redhat 7.1 (seawolf) system. I was able to compile the kernel fine, but my question is what happens to the system when you are not using a redhat distributed kernel (with headers and all)? Are there additional steps people using a custom kernel on a distributed linux should follow to make sure everything is working together? Thanks in advnce.

[bdg1983]

That's a very good question. I've often wondered the same.

Most distros take the kernel they will use as the default for their next release and customize it to a certain extent.

For instance, acpi works fine with my default 2.4.2 kernel, but I can never get it to work with any of the newer kernels. The 2.4.2 default .config has acpi as a module though if I use the same .config for let's say the 2.4.10 kernel, make modules will fail. I either have to say y or n to acpi instead of m. Other things like the gui boot feature is sometimes a custom (patched) feature of the default kernel.

One of these days I'll have to figure out how it is done and how these features can (and if) be patched to the newer kernels.

That's about the extent of my knowledge on the subject.

[thor420]

Well well, I did some looking around and found something that raises a related question. I had been reading about System.map and how you need to have the same System.map in /usr/src/linux and /boot. So I do. But there is another file in /boot that is old. It is module-info-2.4.2-2 (my RH distro kernel). There is no module-info-2.4.10 (my latest compiled kernel). Where would you suppose that file comes from and why would it be absent? Maybe there is something I missed...

[bdg1983]

Only my default 2.4.2 kernel has a symlink in /boot to /usr/src/linux-2.4.2/System.map as my other kernels (2.4.10 and 2.4.12) have the actual System.map copied from /usr/src/linux-2.4.## to /boot/System.map-2.4.##. I don't use symlinks for the newer kernels.

I'm not familiar with module-info-2.4.2-2 as my distro (Caldera) does not have anything like that. I do use a initial ramdisk (initrd) when booting and need to update the corresponding initrd-2.4.## whenever I recompile the kernel.

What is in module-info-2.4.2-2? Is it a text file?

[thor420]

I have the same situation with my System.map file as you do with the newer kernels. They just get put into /boot dir.

Never really new about the initrd file, if you could enlighten me as to what kind of function that may serve I would appreciate it.

The module-info-## file is a text file redhat must build upon installation. It contains many (looks like a ton) of module names and how the are loaded? maybe. This is one of the reasons I decided to recompile my kernel in the first place. Redhat pretty much modulizes *everything*, whether I needed those things or not. I've think that recompiling a kernel to suit my needs made a little more sense - faster, smaller, etc. Why have modules for some piece of hardware I will never own.

Anyway the whole thing is relatively frustrating, understanding what looks at what (symlinks) to provide functionality to an already bloated distro.