[SOLVED] kernel panic-not syncing VFS:unable to mount root fs on unknown-block(8,1)

farmerdave · 09-25-2009, 02:42 AM

I realise that this question has been asked before, i think i did a simple thing wrong which has given me the error message.

I had just finished a LFS 6.4 installation (a success!), and had booted into it just fine, and verified my Slackware installation was still ok, which it was. I went to alter my grub menu, just to switch the default number and add a different vga resolution to the kernel lines.

By mistake, i opened /etc/grub/menu.lst (which actually created the file) I realised this was an empty file, so i then opened /boot/grub/menu.lst, did my changes and then rebooted. It was immediately after this that i am stuck. Cannot boot slackware (gives the error message) and get a blank screen trying to boot LFS.

Any suggestions how to fix?

mazinoz · 09-25-2009, 08:30 PM

Use knoppix CD/DVD to boot or your distros DVD and select 'rescue' mode. Then change menu.lst back to the way it was and boot without CD/DVD.

farmerdave · 09-25-2009, 08:53 PM

Thanks mazinoz, would you agree that my mistake with the menu.lst file is the actual cause?

mazinoz · 09-25-2009, 10:58 PM

Almost certainly.

mobinskariya · 09-26-2009, 04:32 AM

just give the output of following command as root

Code:

fdisk -l

and specify which partition contains which OS.also post the contents of /boot/grub/menu.lst

farmerdave · 10-04-2009, 05:18 AM

Quote:

sudo fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x5e0aec4d

Device Boot Start End Blocks Id System
/dev/sda1 * 1 1245 10000431 83 Linux
/dev/sda2 9606 9729 996030 82 Linux swap / Solaris
/dev/sda3 1246 5689 35696430 83 Linux
/dev/sda4 5690 9605 31455270 83 Linux

Partition table entries are not in disk order

LFS is on /dev/sda4
Slackware is on /dev/sda1 with its home partition on /dev/sda3

farmerdave · 10-04-2009, 05:20 AM

Quote:

# Begin /boot/grub/menu.lst

# By default boot the first menu entry
default 1

# Allow 10 seconds before booting the default
timeout 10

# Use colours
color green/black light-green/black

# The first entry is for LFS
title LFS 6.4
root (hd0,3)
kernel /boot/lfskernel-2.6.27.4 root=/dev/sda4 vga=773
title Slackware
root (hd0,0)
kernel /boot/vmlinuz root=/dev/sda1 vga=773

Here is /boot/grub/menu.lst

farmerdave · 10-04-2009, 05:28 AM

I have tried to chroot back into the lfs environment and create the link

Code:

ln -sv /boot/grub/menu.lst /etc/grub

but when i try and reboot, i get the same error. Then, when using a live cd to work from, it says the link is broken.

mobinskariya · 10-04-2009, 07:46 AM

try reinstalling grub by chrooting into slackware..

farmerdave · 10-05-2009, 07:21 AM

That solved it, Thanks!

AllShk · 11-21-2009, 09:23 PM

Hey guys...
I've got a similar problem with ubuntu 9
but the only thing i did was update some files using the update manager
i was trying to make the wireless network works too and i've activated a driver
then when i was closing the applications to restart the system it crashed.
the screen got black and i couldn't move the pointer
when i restart the pc i got that error message =/
does anybody knows what happened and what i have to do to fix it?
any help will be much appreciated

thanks