Lionhard,

genkernel can do as much or as little of the kernel configuration and build process as your like.
However, its totally brain dead. I does not detect anything. Left to its own devices, it makes a generic totally modular kernel with most of the modules in the kernel tree compiled.

By defualt, it leaves out agpgart, DRM and sound support, which means manual intervention is required for any sound and some graphics cards.

Even on a system thats three or four years old, you can do a manual kernel configure and build faster than genkernel will build you a kernel.

In fact, Genkernel will try to build every drivers that the kernel has, so instead of compiling your lan card driver, it will build maybe 25 drivers just to be sure that it will find your lan card on the reboot.

Genkernel is not optimised at all when we talk about kernel optimization (I mean the number of drivers that Genkernel needs to compile).

The following steps are necessary to change kernel:
- get kernel source
- get initial kernel config "/usr/src/linux/.config" file
- modify kernel config
- compile and install kernel
- compile and install kernel modules
- optionally create and install initial ram disk image
- reboot

The "genkernel" automates most of the steps. ;-)

Right, I mixed with this.

The conclusion I have from the dicussion is that maintaining a large amount of Gentoo Server configured on a special way (hardened in my case) can generate a lot of work compared to a binary distribution.

It depends. If you have to compile your own kernel for some reason, all the distros are equally hard to maintain in this regard.

If you can live with the stock precompiled kernel then it will be easier (at least 99% of the time), no doubt.

After computer (or "server" or "workstation") is installed and configured, the maintenance consist of the only two tasks:
- perform regular backups (to recover in case of hardware malfunction)
- apply security updates (to prevent use of newest exploits)
And there is no big difference between binary and source-based distributions.

I was not precised enough.
When i say binary distro, i mean pre-configured and binary kernel, instead of keeping my "tuning of the kernel" at every kernel released; where I have to re-qualify my kernel every time a kerlen is released.

if I am moving from 2.6.29 to 2.6.30, will copying the .config and then running make oldconfig work?

except the time differences in installing as opposed to compiling packages. a gentoo update can take an hour or more on my laptop, yet maybe 15 minutes or less in debian on the same laptop. I would suggest that is a big difference.

EDIT: Though I compile my own kernels in Gentoo and Debian and they take roughly the same time. So from a kernel point of view yes there is no big difference.

milomak,

It worked for me. I didn't see any major reorganisations of the menu structure.

"make oldconfig" always works as long as you answer the questions in the right way

In fact, always double check your kernel with make menuconfig if you think that something is new or you are not sure about something.

When there something that change that refer to some hardware part, I always double check just to see if it still good.

For example, the intel wireless section changed a couple of months ago.

yeah i normally run make menuconfig after running make oldconfig. But I swear I read somewhere that it was advised not to do oldconfig, hence my question. but glad to see it is not going to cause issue (though it previously hasn't tbh).

oldconfig is not good or bad per sé, you are the responsible for looking over each setting and making sure that the kernel you compile is suitable for your machine. It's good to get an overview of the things that are different between the two versions of the kernel, but oldconfig is not there for automation purposes, and it's not a substitute for the human factor nor for {menu,x}config.