Problem with booting newly compiled kernel

[Prasad Joshi]

Hello,

I seem to be always getting stuck in the new kernel booting. The
problem is with mounting of the root file system. I don't have the log
of the messages but, I guess, these were the messages reported

VFS: Cannot open root device ............
Please append a correct "root=" boot option; here are the available partitions:
Device: sda driver: sd
....... list of all partitions on sda, including correct size, offset
of each parition  .......
Device sdb driver: sr

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Backtrace:

It reported the correct list of sda partitions, including the driver
name as sd. I have a SATA disk and the root partition has ext4 file
system. The ext2/3/4 code is compiled as a part of the kernel.

$ df -kh /
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             459G   13G  423G   3% /


As far as I can understand, as it is showing the correct list of
partitions, the problem is not with the block device driver. But I am
not sure, why it is failing to mount the file system when ext4 is also
part of the kernel.


grub.cfg file.

menuentry 'Ubuntu, with Linux 2.6.37-rc6+' --class ubuntu --class
gnu-linux --class gnu --class os {
        recordfail
        insmod part_msdos
        insmod ext2
        set root='(hd0,msdos5)'
        search --no-floppy --fs-uuid --set ab9dfe8f-8e58-43ca-b16f-a42e0f02da72
        linux   /vmlinuz-2.6.37-rc6+
root=UUID=01432597-18e7-4609-9f85-3fad1d762ddc ro iommu=1
        initrd  /initrd.img-2.6.37-rc6+
}

menuentry 'Ubuntu, with Linux 2.6.35-22-generic' --class ubuntu
--class gnu-linux --class gnu --class os {
        recordfail
        insmod part_msdos
        insmod ext2
        set root='(hd0,msdos5)'
        search --no-floppy --fs-uuid --set ab9dfe8f-8e58-43ca-b16f-a42e0f02da72
        linux   /vmlinuz-2.6.35-22-generic
root=UUID=01432597-18e7-4609-9f85-3fad1d762ddc ro  iommu=1 quiet
splash
        initrd  /initrd.img-2.6.35-22-generic
}

The kernel 2.6.35-22-generic boots correctly.

Thanks and Regards,
Prasad