> 1) I use mainly ReiserFS, except for my /boot partition which is ext2. Can
> I safely omit the initrd if I compile ReiserFS directly into the kernel,
> or is there something else I'd need?

Well, maybe you'll need some IDE drivers. I've always compiled my own
kernels so I don't know exactly how the 2.6.10 package is done. But if you
alread boot-ed with it. See what modules were loaded (whit lsmod), and from
that list you should be able to deduce which drivers should be compiled in
the kernel.

> 2) What exactly does System.map do?

System.map is mostly not used, but sometimes it helps with debuging. Also
klogd may use it when loging stuff (but its not necesseary).

> 3) I have several kernels in /boot, and several according System.map
> files. Question: when my /boot/grub/menu.lst stanza says
> "kernel=/vmlinuz-ide-2.4.29", does this mean that automatically the
> according System.map-ide-2.4.29 will be used (since it bears the same
> appendice)?

Yes, klogd is the only program that automatically tries to use
System.map-xx, and it will try to open System.map-`uname -r`.
The other program that might use System.map is /etc/rc.d/rc.modules... and
it will also try System.map-`uname -r`.

> 4) I tried to recompile the stock 2.6.10 kernel, and the only alteration I
> made was change the processor type from 486 to 586/6x86. I couldn't boot
> on that new kernel, because there was an error about a wrong reiserfs
> module. I *think* I should have repeated mkinitrd, but then...

Offcourse, the modules are intimately tied to the kernel... its usualy not
possible to mix them.

> AFAIK, I should have *two* initrd.gz files in /boot... one for the stock
> 2.6.10 kernel, and another one for the recompiled one. Hence my question
> above, about how to do without an initrd.

I've always favored kernels that can boot without initrd. I guess that may
be a better choice for you too.

--
damjan