LinuxQuestions.org - unable to mount VFS kernel panic, Boot failed.

- Fedora (http://www.linuxquestions.org/questions/fedora-35/)

- - unable to mount VFS kernel panic, Boot failed. (http://www.linuxquestions.org/questions/fedora-35/unable-to-mount-vfs-kernel-panic-boot-failed-841642/)

unable to mount VFS kernel panic, Boot failed.

Hello,
I am trying to install linux kernel manually, for this I had compiled linux-2.6.36 with minimum drivers and features. Note that ext2, ext3, jffs file system support and sd ata_piix drivers are set as inbuilt kernel modules.
I had two hard disk for my Intel x86 box sda and sdb. I have running linux on sdb from which I can access sda. sda has one partition sda1 as ext3 fs.
I had created following directories at sda1 root,
bin, boot, etc, sbin
after compiling kernel, I had copied bzImage, system map files to boot folder. then using 'grub-install' I had installed grub on sda. after installation I edited grub.conf to setup kernel image.
grub.conf

Code:

title Mylinux

root (hd0,0)

kernel /boot/bzImage-2.6.36 root=/dev/sda1 ro

after this I booted sda by changing HDD boot priorities,And wow I got grub prompt -- linux kernel booted but as soon as it tries to mount file system it dies with error,

Code:

kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,1)

I accept that I dont have binaries for init and no initialization stuff in /etc, but I think problem is I am not able to give correct rootfs to kernel.
I googled about that but I am not getting concepts of ramfs initrd..
if anyone knows how to configure rootfs and what can be possible reason of above error please help me.

you need an initrd line to specify your initial ramdisk, it can't find that so you get the kernel panic. look at mkinitrd or mkinitramfs for the building of one

I found that we need ramfs in order to mount actual rootfs for linux 2.6.* kernel. rootfs needs some basic directory structure and files with valid contents. I am searching for information about basic rootfs and all files with valid contents or entries used in linux. Please give any link or information which describes all this in details and which I can experiment with my x86 linux box. being more specific I need info about /dev and /etc directories contents, init dependencies.

Take a look busybox it can fill all the needs of the basic directory structure and files as well as being init itself.

http://www.busybox.net

The only other things you need are the basic devices (look at MAKEDEV) and probably an /etc/passwd (/etc/shadow) /etc/group files and an /etc/inittab (but busybox style)