Kernel panic: VFS: Unable to mount root fs
 

This is my first question on this list :-)

I've Slackware 10.2, kernel 2.4.x. The / fs is on ext3 on device /dev/hda2. Use lilo to boot.

I compiled kernel 2.6.17.11 with ext3 fs support. Updated lilo.conf and executed it. Rebooted and got this error message:

<snip>
VFS: Cannot open root device "032" or unknown-block(3,2)
Please append a correct "root=" boot option
Kernel panic: VFS: Unable to mount root fs on unknown-block(3,2)
</snip>

For some reason the new kernel is not able to find my / fs. I've specified the / (/dev/hda2) in lilo.conf. Ext3 support is built-in and not in modules.

And, I'm still able to boot using the old kernel. I trawled the net searching for an answer, and realised that lot of guys are encountering the same problem with kernel 2.6.x!! Is this a known issue? Any solutions?

Thanks,

Ajay

could you paste your /etc/fstab and lilo.conf file here.
shouldnt this be (0,2)

Exact same thing happened. . . Slackware, Ext3 filesystem, compiled 2.6.17 kernel, Lilo. . . Kernel panic! Can't mount root. Took me a weekend to figure it out.

Re-run kernel config, make sure Ext3 file system is selected to compile in (not as a module), and rebuild.

Thanks,
Mark

I too had this problem under Gentoo (well, actually, still have...) when I compiled the 2.6.17 kernel. I made sure that ext3 (for that is what my root is on) support was compiled in, and have tried it with ReiserFS also. I haven't found a solution yet (then again, I just started looking). Any tips?

Nigel Macphereson

lilo problem
 

Very Maybe, but maybe it could be lilo?
In the lilo entry for that operating system it may not have a line for the root device.

something like root=/dev/hda3
(I think that is the syntax)

Hope this helps.

I had the same problem and it was because I had not compiled in support for my IDE chipset during make menuconfig.

Check the settings under ATA/ATAPI/MFM/RLL Support for your particular chipset.

Without IDE support the kernel cannot run the harddisk.

whats a lilo?????

ah...
I did a google "define" for you

have the same issue on arch 0.7.2 ,, just compiled the 2.6.18 kernel .. root on /dev/hda2 .. grub entries perfect .. same error ..

on second thought. i removed support for ext2 from the kernel and only kept ext3 ... could that be an issue ?

You can also use the "Search" function at the top of the menu, on keys "VFS: unable to mount root", searching in the "Titles Only" option, as this question has been asked in 78 different threads. It's usually one of two things, as I wrote here (different hardware and filesystem, same concept):

http://www.linuxquestions.org/questi...+to+mount+root

Others:
http://www.linuxquestions.org/questi...d.php?t=360249
http://www.linuxquestions.org/questi...d.php?t=241747
http://www.linuxquestions.org/questi...ad.php?t=36608


Depends on what the root filesystem has been set to. Your root=/dev/whatever is translated into a number. Check out devices.txt in /usr/src/linux/Documentation. It's usually 3,something due to...

Also depends on how the disk controllers are setup. I've got a /dev/hda1 and also a /dev/hde1 as roots in two machines.

Doesnt help
 

I will try not to be as snobby as some earlier reply but anyways the links provided dont work anyway .. :)