Can someone explain me the reason why in the debian distributions all the filesystem kernel modules are not compile inside the kernle but loaded at the boot using the initramdisk??
For example why the ext3 module which is vital is not compile in the kernel???

Thanks

If all of the kernel modules were compiled into the kernel then the kernel would be too big to boot into most machines. So only the kernel modules that are actually needed are loaded with the kernel. When you compile your own kernel you can compile the exact configuration of modules you need into your kernel.

The problem that distributions like Debian face is that what modules need to be compiled into the kernel varies widely from machine to machine. So the distributions solve that problem by compiling no loadable modules into the generic kernels they distribute thus creating a fairly small kernel. Then at install they decide which loadable modules need to be loaded at boot for this particular machine and set up an initrd to read in those modules in along with the generic kernel.

While ext3 may be essential for you there are many people who do not use ext3 for their / partition or perhaps don't use ext3 at all. For these people having ext3 compiled into their kernel would be unnecessary bloat.

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Steve Stites