Hello guys,

I am running a slackware13.37 64 bit. I downloaded a linux 3.2.1 kernel from kernel.org and compiled it with default options and an initrd. Now when I try to boot from the kernel it gives a kernel panic and gives message which says some error in loading ext4.ko.

The logs are
...
Loading kernel modules from initrd image:
using /lib/modules/3.2.1/kernel/fs/ext4/ext4.ko
insmod: not configured to support older kernels.
....
ERROR: /dev/sda1 on /mnt failed. No such device...

I can see that while loading the initrd the insmod is failing, Would it be something to do with the 3.X range of kernels. Please let me know if there is something that i am doing wrong.

Thanks
Shridhar

You need to update/rebuild your initrd. It contains modules from the older kernel, so when the initrd script tried to load the necessary modules to mount the root file system, this happens:

insmod: not configured to support older kernels.

Here's a guide to building a kernel, adapt the release numbers to suit:
http://alien.slackbook.org/dokuwiki/...kernelbuilding

Hello Olmy,

I had a stock kernel initially which did not have a initrd. I built this new kernel 3.2 and an initrd with it.

command used:
mkinitrd -c -k 3.2.1 -m mbcache:jbd:ext4 -f ext4 -r /dev/sda1
"-c option wipes out the existing initrd if at all it exists"

is there anything more that i need to do.

That is a bit odd. Your mkinitrd parameters seem perfectly fine, including "-k 3.2.1". Did you run "make modules_install" before running mkinitrd? And you didn't build the 3.2.1 kernel with a custom suffix?

Take a look in /boot/initrd-tree/lib/modules. There should be a "3.2.1" subdirectory containing the modules for the 3.2.1 kernel.

when you built your kernel did you use the one of the config files from /boot or did you just download and untar the 3.2 kernel and go from there. Most problems with booting a newly compiled kernel involves not having all the drivers/items built directly into the kernel or as modules. To get a kernel to boot without an initrd your need the filesystem your using and drivers for you hard drive controllers built into the kernel. When you built your kernel did you select ext4 under the filesystem section and the correct drivers for your hardware. Without knowing what kind of hardware you have and what your did or did not build into your kernel, there is not very much advice any one can really give you. The thing about building a kernel is that you have to know your hardware and what filesystems you will be accessing.

Hello,

I was using existing config file "2.6.29.6-generic", may be as you said some hardware drivers were missing. So tried out with config file of "2.6.19.6-huge" without any changes and it worked. Will go backwards now and try and remove unwanted modules etc.

Thank you guys for all the help. Its a lovely community :-)

Shridhar Shetty