i compiled a 2.4.19 kernel on my server and i got no more network !
ifconfig shows that it should be ok, so as route and my NAT/firewall script (arno's iptalble script) shows same output as usual but my network is down: no more samba from my xpbox and no more internet from anywhere
reverting to 2.4.18-bf2.4 solve the problem.
whats wrong?

i got no clue

There should be no major differences between the two kernel versions.

Did you make any kernel configuration changes compared to the stock 2.4.18-bf2.4?

If you are unsure, make a diff between
/boot/config-2.4.18-bf2.4
and
/usr/src/linux-2.4.19/.config

(or whereever your kernel source is located)

What differences show up?

If any, you might first try the easy way: copy /boot/config-2.4.18-bf2.4 to /usr/src/linux-2.4.19/.config

and re-compile/-install (after doing a "make clean" in the kernel source directory)


Regards
ric.

diff shows a lot of output since my 2.4.18 kernel was the one supplied with the disto while my 2.4.19 is one i configured myself with menuconfig.

i'm considering trying your solution, using the 2.4.18 config for the 2.4.19 but there's something i dont understand: if the kernel is newer, there's should be differences between config option right ? how can this work ?

i'm gonna recheck my network config in my newer kernel to see if i did not miss something but thats strange cause i cheched almoste every options for network supporting. But maybe some are incompatible with others ??

The kernel config file is simply a list of parameters to set up how any part of the kernel is compiled. They can be set to either "y" (compile hard into the kernel), "m" (compile as a module) or "n" (don't compile). If a parameter is not set at all, it defaults to "n".
All that make [config | menuconfig | xconfig] does is to provide a human readable interface to that list.

Usually there are not many changes between single steps of the kernel version. Especially rarely a config option is removed, and new options are mostly not needed to get the kernel working like before.

The only problem you can run into is when you change a distro's heavily patched kernel into a vanilla one from kernel.org. Then some things (like IPsec in kernel 2.4 or User Mode Linux) surely will be broken. But this is regardless of the config file you use.
Also, as Debian does only moderate patching, it is more likely that you don't run into patch related problem than on, say, Red Hat or SUSE.

When starting off with a new system, my first step is to compile the current kernel with the stock config file (except for setting processor type and adding special drivers needed for this machine).
When that works (and I have some time to spend ;-), I step by step reduce features that are unnecessary for that machine.
It's surely a better way than building your own kernel config from scratch and try around until it works ;-)


Regards
ric.

Ok i tried using /boot/config-2.4.18-bf2.4 as a config file for my 2.4.19

the kernel compiler, but, strangely, things like iptables are missing and of course my firewall complains

i dont understand why this happen since everything was fine with my 2.4.18

i did not forget to make modules and make modules_install

i'm gonna do the wole thing again and check the network config but before, could u tell me how do u tell make that u want everything installed in /boot and not in /

thx a lot for your help

Missing modules:
do the iptables modules (and whatever else you're missing) exist somewhere below
/lib/modules/2.4.19 ?

iptables modules should be in
/lib/modules/2.4.19/kernel/net/ipv4/netfilter

Did you do a make clean before make menuconfig? Did you do a make dep after menuconfig?

Does your 2.4.18-bf2.4 use an initrd (best check in /etc/lilo.conf)? Then it might be that the iptables modules are loaded there when booting 2.4.18

There should either exist entries for the iptables modules in /etc/modules or the firewall script should insert them.


Putting the kernel to /boot:

I didn't know there was a make target to install the kernel. Do you use any tool (like kernel-package) to actually build the kernel?

Usually after make modules_install I copy the kernel and System.map manually, like:

cd /usr/src/linux-2.4.19
cp arch/i386/boot/bzImage /boot/vmlinuz-2.4.19
cp System.map /boot/System.map-2.4.19

then edit /etc/lilo.conf to match the new kernel; add a block like

image=/boot/vmlinuz-2.4.19
label="Linux_2.4.19"
read-only

and make the new kernel the default one.

Then run lilo to actually activate the new configuration.


Regards
ric.

the iptables modules is not in /lib/modules/2.4.19/kernel/net/ipv4/netfilter. How can this be since i checked this module in menuconfig and made modules and modules_install ??

i believe i did a make clean and make dep but not sure, gonna retry

>>Does your 2.4.18-bf2.4 use an initrd (best check in /etc/lilo.conf)? Then it might be that the iptables >>modules are loaded there when booting 2.4.18

i looked at my /etc/lilo.conf and the word initrd doesnt show up. since i dont know what is initrd i quickly had a look at man initrd but i dont understand what u mean by that module loaded by initrd...

no iptables entry in /etc/modules but my firewall script does a modprobe ip_tables somewhere.
while looking at the script, i realized again that there is many modules under /lib/modules/2.4.19/kernel/net/ipv4/netfilter that the script attempt to load and since there in nothing, we have the same problem of missing modules...

i must find out why the expected modules are not installed properly

>I didn't know there was a make target to install the kernel. Do you use any tool (like kernel-package) to >actually build the kernel?

nope, but there is a make install feature in the kernel source packages. I can recall that i read that this feature is quite new but i cant tell since wich kernel source version number

i used to install the thing manually but since there is a feature wich does it by itself i prefer letting it do the work so i'm sure i do no forget to do something.
but the default setting is putting everything in / , not in /boot and i suppose there is an argument to pass to make install to have what i want done.
instead, i mov the files from / to /boot and check lilo.conf myself so i should go back to the old method ...

Concerning initrd:
initrd is short for "initial RAM disk". This RAMdisk is loaded/mounted #before# the root file system. It usually contains kernel modules that are necessary to boot the system, typically drivers for hard drive controllers, sometimes network drivers. But you can force any kernel module into an initrd.


Now back to your problem.
Maybe you should try to start all over. This might be better than digging around for something you might have missed. At least this is my method when I'm completely stuck with something ;-)

I suggest you do the following:

- remove any lines related to kernel 2.4.19 from lilo.conf
- run lilo
- remove kernel 2.4.19, and System.map 2.4.19 from /boot
- remove /lib/modules/2.4.19
- remove /usr/src/linux-2.4.19
- remove the symlink /usr/src/linux if it exists
- unpack, configure and install the kernel, like:

tar xjfv /path/to/kernel/source/archive/linux-2.4.19.tar.bz2 /usr/src
(or tar xzfv if you have the .tar.gz version)
cd /usr/src
ln -s linux-2.4.19 linux
cd linux
make mrproper (normally not necessary, but just to be sure ...)
cp /boot/config-2.4.18-bf2.4 .config
make menuconfig
For now, change only the processor type to your machine's, then exit menuconfig and save the new kernel configuration
make dep
make
make modules
make modules_install
cp arch/i386/boot/bzImage /boot/vmlinuz-2.4.19
cp System.map /boot/System.map-2.4.19

- Add the following lines to /etc/lilo.conf:

image=/boot/vmlinuz-2.4.19
label="Linux_2.4.19"
read-only

- also add (if you don't have these):

prompt
timeout=50
default="Linux_2.4.19"

- run lilo and reboot


What happens? Do networking and iptables work?


Regards
ric.

it works


but i dont know why !!


yes i know the modules are there but i dont know why they wouldnt install previoulsy


anyway thx A LOT for your support ricstirato, guys like you help the linux community to be what it is.

bye

I'm sure there has been something really simple you missed. Especially forgetting make clean or make dep are very popular.

Anyway it's been an honour to serve you ;-)