Hi Guys ,
I need advise from you guys as when i finish compile kernel then after i rebbot the server and i get the error message like below :

VFS: Cannot open root device "hdc2" or unknown-block(0,0)
Please append a correct "root=" boot option
kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)


Can somebody help me how to solve this problem and one more thing can somebody advise me how to configure grub.conf correctly ?

Thanks Guys

First, Linux is not a distribution, it is the kernel. The other apps and
different things included in addition to the kernel make an OS. If you
put your Linux distribution it will be easier to help you when you post.

This kernel panic means you don't have support for your root filesystem,
or the hard drive device, in your kernel. So, you can look and see what
you've compiled in the kernel. If you can't figure it out, post the output of:

/sbin/lspci
grub.conf
cat /etc/fstab
and your kernel .config file

Opsss .. sorry .. the linux distribution is Red Hat 9.0

Here is my grub.conf

splashimage=(hd0,4)/boot/grub/splash.xpm.gz
title Red Hat Linux (2.4.20-8)
root (hd0,4)
kernel /boot/vmlinuz-2.4.20-8 ro root=LABEL=/
initrd /boot/initrd-2.4.20-8.img

title Red Hat Linux (2.6.11)
root (hd0,4)
kernel /boot/kernel-2.6

x-radian,

Change that in your LQ UserCP so that we can tell
just by looking at your posts.

I don't know about GRUB -- couldn't figure it out so
I use LILO. But the problem with your kernel panic
is probably either you don't have your root filesystem
built into the kernel; or you don't have your IDE device
built in. Those cannot be modules unless you use an
initrd image.

ok ... that interesting if you can guide me how to use lilo

Please post that other output -- and someone else can help you use
grub I'm sure. It looks to me like you're telling grub to mount (hd0,4)
which to me would be /dev/hda4 (or /dev/hda5 if you have extended
partitions). Then the kernel says it's trying to locate your / filesystem
at "hdc2" or unknown-block(0,0) --- and /dev/hdc2 would be something
like (1,2) if I'm correct. See why I use LILO? You use the device name
and it's done.

That other output will tell us what you've got that's causing this kernel
panic.

If you really want to use LILO rather than GRUB, I can tell you exactly
how to configure LILO, but not how to remove GRUB.

Did you build an initrd image for the new kernel? At the moment there isn't any reference to it for the 2.6 kernel. If you ran the mkinitrd command and built the image correctly you should be able to just append the line into GRUB - similar to the existing initrd line for the 2.4 kernel.

That may help - but I'm not familiar with the root option on the 2.4 kernel there.