KC13. Kernel panic: VFS: Unable to mount root fs

Nergal · n00b Joined: 08 Jan 2004 Posts: 4

Hi,

I have been searching the forums and bugs for some hours and I have read this question in the FAQs forum, though I didnt find the answer. This is exactly my problem. As I read that as a bug, being the solution that the user made a mistake, I decided to question about it here.

The problem: unable to mount root fs at boot.

The message:
ds: no socket drivers loaded!
VFS: Cannot open root device "hdb5" or 03:45
Please append a correct "root=" boot option
Kernel panic: VFS: Unable to mount root fs on 03:45

The solutions I have read about, and tried (they dont work here though), but I write them in case they are useful for someone else:

Kernel configuration failures:
- having reiserfs and not compiling into kernel
- having ide and not compiling into kernel

My own case:
What I have made while the instalation ( I write all the strange messages, perhaps they are useless, but I dont know):

While emerge system:

Error while merging x11-base/xfree-4.3.0-r3
Error while merging dev-lang/tk-8.3.4-r1

While compiling on my own: no problem.
When making VIDEO-CARDS = "Matrox" emerge xfree-drm error
While compiling with genkernel: error con ide-cs.o

I have an Athlon 700 MHz, 128 Ram, Matrox Millenium G-450.
I have revised fstab and grub conf. I have ext2 for boot partition and reiserfs for the rest of Linux partitions.
reiserfsck was OK.
Both reiserfs and ide were ON in kernel config.

Thinking about a user-failure in kernel config I tried with genkernel, but it didnt worked anyway.

Can anyone help me with own experience or ideas?

If somebody wants to help and need more data ask freely. I will be glad to answer.

Thanks in advance.

Nergal.

paranode · l33t Joined: 06 Mar 2003 Posts: 679 Location: Texas

Like you say, there are usually a handful of reasons this will happen. Usually it's that (in your case) hdb5 is not the right root partition, you left out support for a filesystem that the kernel is trying to mount, or you did not compile in the correct chipset support in the kernel.

Let's see the output of lspci or if you don't have that, then cat /proc/pci and fdisk -l /dev/hdb
_________________
Meh.

Nergal · n00b Joined: 08 Jan 2004 Posts: 4

From cat /proc/pci I get:
PCI devices found:
Bus 0, device 0, function 0:
Host bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133] (rev 3).
Prefetchable 32 bit memory at 0xd0000000 [0xd3ffffff].
Bus 0, device 1, function 0:
PCI bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133 AGP] (rev 0).
Master Capable. No bursts. Min Gnt=12.
Bus 0, device 7, function 0:
ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super South] (rev 34).
Bus 0, device 7, function 1:
IDE interface: VIA Technologies, Inc. VT82C586B PIPC Bus Master IDE (rev 16).
Master Capable. Latency=32.
I/O at 0xd000 [0xd00f].
Bus 0, device 7, function 2:
USB Controller: VIA Technologies, Inc. USB (rev 16).
IRQ 9.
Master Capable. Latency=32.
I/O at 0xd400 [0xd41f].
Bus 0, device 7, function 3:
USB Controller: VIA Technologies, Inc. USB (#2) (rev 16).
IRQ 9.
Master Capable. Latency=32.
I/O at 0xd800 [0xd81f].
Bus 0, device 7, function 4:
Host bridge: VIA Technologies, Inc. VT82C686 [Apollo Super ACPI] (rev 4

.
IRQ 11.
Bus 0, device 7, function 5:
Multimedia audio controller: VIA Technologies, Inc. VT82C686 AC97 Audio Controller (rev 32).
IRQ 10.
I/O at 0xdc00 [0xdcff].
I/O at 0xe000 [0xe003].
I/O at 0xe400 [0xe403].
Bus 0, device 17, function 0:
Ethernet controller: Linksys Network Everywhere Fast Ethernet 10/100 model NC100 (rev 17).
IRQ 11.
Master Capable. Latency=32. Min Gnt=255.Max Lat=255.
I/O at 0xec00 [0xecff].
Non-prefetchable 32 bit memory at 0xda000000 [0xda0003ff].
Bus 1, device 0, function 0:
VGA compatible controller: Matrox Graphics, Inc. MGA G400 AGP (rev 130).
IRQ 11.
Master Capable. Latency=32. Min Gnt=16.Max Lat=32.
Prefetchable 32 bit memory at 0xd4000000 [0xd5ffffff].
Non-prefetchable 32 bit memory at 0xd6000000 [0xd6003fff].
Non-prefetchable 32 bit memory at 0xd7000000 [0xd77fffff].

From fdisk -l /dev/hdb

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

Device Boot Start End Blocks Id System
/dev/hdb1 * 1 6 48163+ 83 Linux
/dev/hdb2 7 70 514080 82 Linux swap
/dev/hdb3 71 1287 9775552+ c Win95 FAT32 (LBA)
/dev/hdb4 1288 9729 67810365 5 Extended
/dev/hdb5 1288 3112 14659281 83 Linux
/dev/hdb6 3113 4937 14659281 83 Linux
/dev/hdb7 4938 9729 38491708+ 83 Linux

From cat /etc/fstab
# /etc/fstab: static file system information.
# $Header: /home/cvsroot/gentoo-src/rc-scripts/etc/fstab,v 1.13 2003/07/17 19:55:18 azarah Exp $
#
# noatime turns off atimes for increased performance (atimes normally aren't
# needed; notail increases performance of ReiserFS (at the expense of storage
# efficiency). It's safe to drop the noatime options if you want and to
# switch between notail and tail freely.

# <fs> <mountpoint> <type> <opts> <dump/pass>

# NOTE: If your BOOT partition is ReiserFS, add the notail option to opts.
/dev/hdb1 /boot ext2 noauto,noatime 1 2
/dev/hdb5 / reiserfs noatime 0 1
/dev/hdb2 none swap sw 0 0
/dev/hdb6 /home reiserfs noatime 0 2
/dev/hdb7 /data reiserfs noatime 0 2
/dev/hda1 /mnt/windows vfat noauto,user 0 0
/dev/hdb3 /mnt/windows/data vfat noauto,user 0 0

/dev/cdroms/cdrom0 /mnt/cdrom iso9660 noauto,ro,user 0 0

# NOTE: The next line is critical for boot!
none /proc proc defaults 0 0

# glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for
# POSIX shared memory (shm_open, shm_unlink).
# (tmpfs is a dynamically expandable/shrinkable ramdisk, and will
# use almost no memory if not populated with files)
# Adding the following line to /etc/fstab should take care of this:

none /dev/shm tmpfs defaults 0 0

none /proc/bus/usb usbfs defaults 0 0

And, finally: grub.conf
default 1
timeout 7
splashimage=(hd1,0)/grub/splash.xpm.gz

title=Linux
root (hd1,0)
kernel (hd1,0)/kernel-2.4.22 root=/dev/hdb5
initrd (hd1,0)/initrd-2.4.22-gentoo-r2

title=Windows
root (hd0,0)
chainloader (hd0,0)+1

HermanR · Posted: Thu Jan 08, 2004 8:50 pm Post subject:

Seems like I have the same problem:

I have installed gentoo using a default genkernel (gentoo-sources) and Grub as bootloader. My root filesystem is on a ReiserFS-filesystem. As far as I can tell, support for ReiserFS is in the kernel itself. (Or am I mistaken???) I am also quite positive that the location of my root filesystem (/dev/hde10) has been correctly identified in grub.conf.

When I boot, Grub starts op fine, and the kernel also comes up, ben then I get a kernel panic, stating that /dev/hde10 cannot be found.

paranode · l33t Joined: 06 Mar 2003 Posts: 679 Location: Texas

Someone in another post mentioned that enabling advanced partition types -> PC BIOS partitions in the file system section fixed this kind of problem for them. Might give that a try.
_________________
Meh.

Nergal · n00b Joined: 08 Jan 2004 Posts: 4

Thanks for the advice, but unfortunately it didnt work. The genkernel had activated that option yet. :-(

HermanR · Posted: Fri Jan 09, 2004 3:26 pm Post subject: of course!

My gentoo now works. I had overlooked a driver in the kernel, which I really thought I had included, but in fact only compiled as module.

My harddisk is on a secondary IDE-adapter and the kernel needs a specific driver to recognize it.

Now on to more interesting stuff!

darkcoder · Posted: Fri Jan 09, 2004 8:40 pm Post subject:

I got the same problem, but only with genkernel 2.0+ when using the bootsplash option. Without bootsplash it worked fine, at least with me.
_________________
Not bleeding edge.... No pain no game :twisted:

Nergal · n00b Joined: 08 Jan 2004 Posts: 4

I also use a secondary driver. Could you please tell me something about your adapter and what kernel changes I should make?

Thank you.

lighty14 · Tux's lil' helper Joined: 11 Jan 2004 Posts: 111

Hi, I'm having the same problem. My harddrive is on a seperate controller card in the computer, do I need to add something to my genkernel for this to work correctly? Will it work if I switch my harddrive onto the first IDE channel on my mobo? This really has me somewhat stumped, and very frustrated.

Dodgeram01 · Posted: Mon Jan 12, 2004 2:30 am Post subject:

Try adding

lighty14 · Tux's lil' helper Joined: 11 Jan 2004 Posts: 111

Tried real_root and I double checked my fstab and grub configs. I'm going to be reinstalling grub in just a few minutes... If I still can't get it to work, I may just use LILO for the time being.

lighty14 · Tux's lil' helper Joined: 11 Jan 2004 Posts: 111

LILO failed to install because I have an older CD. I'm going to download the new CD's and see if I get any luck, if not I may have to just install RHS or SuSE

Suicidal · l33t Joined: 30 Jul 2003 Posts: 959 Location: /dev/null

If you are using the newer genkernel you need to read the readme in /usr/share/genkernel

(all information from genkernel 3.0.1_beta3 readme)

A grub entry should look like this for genkernel 3.0+:

darkcoder · Posted: Mon Jan 12, 2004 9:31 pm Post subject:

I will try with the settings you gave, but the only two I don't have are:

my /etc/fstab