Solved

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

Posted on 2008-10-18
5
6,622 Views
Last Modified: 2013-11-15
Hi all,

I have a problem with my Ubuntu system.  Last week I was installing available updates.  I left my computer alone and my wife turned it off while the updates were still being installed.  Now I can't boot into Ubuntu.  This is the error that I get:

[     1.072000] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

I don't really want to reinstall Ubuntu since I will take me days to customize it like I had it.  Can someone please help me recover Ubuntu on my machine?

Details:
Ubuntu 8.04 / dual boot with Windows XP Home Edition. (GRUB loader works fine and allows me to choose an OS; XP loads, but not Ubuntu)
0
Comment
Question by:ubuntuguy
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
5 Comments
 
LVL 4

Expert Comment

by:larsga
ID: 22749665
The general steps would be:
- Boot from a Live-CD (the normal Ubuntu Desktop install cd will do the job nicely)
- Mount the HD partition that Ubuntu is on as rw.
- chroot to the ubuntu partition
- Run whatever commands you need to repair your system (in your case, a "sudo apt-get update && sudo apt-get upgrade" should probably be sufficient)
- Exit from chroot
- Unmount the partition
- Reboot

A bit more details can be found at http://ubuntuforums.org/showthread.php?t=157250

If you get stuck at one of the points in my list above, please don't hesitate to ask (the exact commands / what you need to click depends a bit on what live-cd you use, the steps I listed above are generic instructions that should work no matter which Linux you have).
0
 
LVL 1

Author Comment

by:ubuntuguy
ID: 22750080
Thanks Iarsga,

I mounted the partition in which Ubuntu is.  The name is "41.9 GB Media".  The problem is that I don't get an option to mount as RW.  I can mounted, but I don't get an option for read/write. When I go to properties and click on permissions, it says "the permissions of disk could not be determined". Under properties-> Volume-> Settings, I get the following options.
Mount Point:
File System:
Mount Options:

Should I choose Mount Point = "/", File System = Ext2, Mount Options = RW? or something similar?
0
 
LVL 4

Accepted Solution

by:
larsga earned 500 total points
ID: 22750159
Are you able to see what the device node is (that is, something like /dev/hda2 or /dev/sda3)?

If so, open a terminal and do this:

sudo su
mkdir /mnt/rescue
mount /dev/hda3 /mnt/rescue      (replace hda3 with whatever the correct partition is)
mount -o bind /proc /mnt/rescue/proc
mount -o bind /dev /mnt/rescue/dev
chroot /mnt/rescue /bin/bash

If the above give no errors, you should now have the equivalent of a root shell on the Ubuntu Linux on your HD. Do the sudo apt-get update/upgrade and whatever else is necessary to repair it. Then you 'exit' or Ctrl-D to exit out of the chroot. Then 'umount /mnt/rescue' and do a reboot.

If the above gives an error (like /bin/bash not found), then your Linux install is probably spread over multiple partitions (one for /boot, one for / and one for /home, for example). If so, please give me the output of 'sudo fdisk -l' and we'll figure out which is which.
0
 
LVL 1

Author Comment

by:ubuntuguy
ID: 22750299
Great!!! Thanks Iarsga.  I got past the GRUB menu.  Ubuntu wouldn't boot at first.  Went into recovery mode and it fixed itself.  It drags a bit now after logging in, but I got my system running again.

Thanks a lot again.
0
 
LVL 4

Expert Comment

by:larsga
ID: 22750344
No problem. Doing recovery on a Linux system that fails to boot is really surprisingly easy once you know how to go about it, and is a skill that I wish more Linux users had.

The basic steps (boot from external media. mount the partitions(s) below some directory (example /mnt/recovery), chroot to this directory, do the commands needed to fix the system, exit chroot, reboot) are valid for pretty much any Linux system and lots of other Unix systems too.
0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Attention: This article will no longer be maintained. If you have any questions, please feel free to mail me. jgh@FreeBSD.org Please see http://www.freebsd.org/doc/en_US.ISO8859-1/articles/freebsd-update-server/ for the updated article. It is avail…
Linux users are sometimes dumbfounded by the severe lack of documentation on a topic. Sometimes, the documentation is copious, but other times, you end up with some obscure "it varies depending on your distribution" over and over when searching for …
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
Learn how to find files with the shell using the find and locate commands. Use locate to find a needle in a haystack.: With locate, check if the file still exists.: Use find to get the actual location of the file.:
Suggested Courses

739 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question