boot custom kernel and /etc/fstab

[Steve Phillips]

On Tue, 2 Nov 2004, Noah wrote:

> using:  Redhat-enterprise WS version 3
>
>
> I just built a custom kernel using the 2.4.21-20.EL source rpm.  it simply
> does not boot and claims a VFS error and is unable to open root device "LABEL=/"
>
> here is a screen picture of the error:
> http://www.enabled.com/~noah/pictures/screen/IMG_0062.jpg
>
> I dont know what exactly I need to do here.  what is a safe, easy way to fix
> this problem so I can boot my custom kernel.
>
>
> --- cat /etc/fstab ---
>
> # cat /etc/fstab
> LABEL=/                 /                       ext3    defaults        1 1
> LABEL=/boot             /boot                   ext3    defaults        1 2
> none                    /dev/pts                devpts  gid=5,mode=620  0 0
> none                    /proc                   proc    defaults        0 0
> none                    /dev/shm                tmpfs   defaults        0 0
> /dev/sda3               swap                    swap    defaults        0 0
> /dev/cdrom              /mnt/cdrom              udf,iso9660
> noauto,owner,kudzu,ro 0 0

you need to either compile in support for disk labels (if you find out how 
to do this please let us know) or change the system to mount/boot based on 
raw devices.

for raw devices change fstab
> LABEL=/                 /                       ext3    defaults        1 1
> LABEL=/boot             /boot                   ext3    defaults        1 2

to
/dev/sda2                 /                       ext3    defaults        1 1
/dev/sda1                 /boot                   ext3    defaults        1 2

You will also wish to change the corresponding lines in /etc/grub.conf 
(assuming you are using grub)

from
         kernel /vmlinuz-2.4.21-20.ELsmp ro root=LABEL=/

to
         kernel /vmlinuz-2.4.21-20.ELsmp ro root=/dev/sda2

where the "kernel" line points to the correct kernel image to boot

then reboot and all should be right

HTH,

-- 
Steve.