[SOLVED] kernel panic

doughyi8u · 08-18-2012, 03:11 PM

I just configured a kernel and installed it. The problem is when I try to boot into it I get the following message:

Code:

VFS: Cannot open root device "801" or unkown block (8,1): error -6

Please append a correct "root=" boot option; here are the available partitions:

Kernel panic - not syncing: VFS: unable to mount root fs on unkown_block(8,1)

I'm guessing I left something out that the kernel needs to boot b/c I installed a default kernel configuration under the same kernel (3.5) and it works fine.

Didier Spaier · 08-18-2012, 03:23 PM

Possibly neither did you configure the file system for your root partition as built in nor did you include the module for it in an initrd (or didn't reference that initrd in /etc/lilo.conf).

doughyi8u · 08-18-2012, 03:29 PM

I thought the same thing but checked that and it is configured. I'm using ext4

Celyr · 08-18-2012, 03:33 PM

So boot your kernel appending the root directive
like
kernel root=/dev/sda1

doughyi8u · 08-18-2012, 03:37 PM

Where would I put this?
I have my lilo.conf as follows:

Code:

image = /boot/vmlinuz
  root = /dev/sda1
  label = Linux
  read-only

Celyr · 08-18-2012, 03:43 PM

Well, you could do it on lilo command line but if you can edit lilo.conf then you are in advantage, just find out what partition is your root typing

Code:

mount

doughyi8u · 08-18-2012, 04:57 PM

so you're saying use

Code:

kernel root=/dev/sda1

In place of

Code:

root = /dev/sda1

?

I'm not familiar with the "kernel root" command in lilo.conf

AlleyTrotter · 08-18-2012, 05:13 PM

I am going to say something silly but:
every time I have gotten this error it was
because
I forgot to run lilo after modifying lilo.conf

john

doughyi8u · 08-18-2012, 05:19 PM

Good thinking alleyTrotter but I made sure I ran lilo more than once

sgmart · 08-18-2012, 05:59 PM

Hello @doughyi8u

I had a similar trouble some days ago, I solved that putting this:

Code:

root = "UUID=uuid_of_your_root_partition"

to /etc/lilo.conf file, and running lilo command again after changes.

The uuid is obtained executing:

Code:

blkid /dev/sdaX

as root.

I hope this solve your problem!

doughyi8u · 08-18-2012, 08:03 PM

sgmart: I tried that and get the same result.

Like I said, I used the default kernel configuration for the 3.5 kernel and it boots that just fine. I made a lot of changes to the default .config and it won't boot with that. I thought for a while that it could be b/c I didn't configure any scsi devices and added those to the .config and re-ran make. I tried that config and get the same results.

Didier Spaier · 08-19-2012, 06:48 AM

We need a little more information to help you.

1) What is your Slackware version?
2) What do you mean "by the default configuration for the 3.5 kernel"?
3) Did you download the kernel source from a kernel.org mirror?
4) Why do you need a 3.5 kernel? Does one of your hardware devices miss a driver in the provided Slackware kernels?
5) What is the purpose of the changes you made in the default .config?
6) How did you make these changes?

To compile a kernel for Slackware, read this how-to from Alien Bob, one of the main Slackware contributors.

Other than that, to help us investigate you could append to your next post two .config files (one with which you could make a booting kernel a one with which there was a problem), respectively renamed as goodconfig.txt and badconfig.txt.

Also, outputs of "lspci -k" and "uname -a" would be useful.

PS To investigate yourself, if you think you miss some driver, look at output of "lspci -k" and check in the "bad" .config that all drivers/modules listed are present in this configuration. Or check that with the "search" feature of your configuration command ("/" for make menuconfig, Ctrl+F for make xconfig).

H_TeXMeX_H · 08-19-2012, 08:33 AM

Maybe posting the .config will help.

turtleli · 08-19-2012, 08:56 AM

Have you checked whether you have enabled the correct SATA/PATA drivers? I've had my kernels fail to boot for that reason.

doughyi8u · 08-19-2012, 05:56 PM

I'm using Slackware 13.37

What I mean by default .config is the .config you get when you run make menuconfig (or make xconfig) and change nothing. When I compile that .config, it starts fine.

I downloaded the kernel from www.kernel.org

The config that works is attached as good_config.txt and the one I'm trying to compile that's giving me problems is config.txt.

Here is the output from "lspci":

Code:

00:00.0 Host bridge: Intel Corporation 82850 850 (Tehama) Chipset Host Bridge (MCH) (rev 02)
00:01.0 PCI bridge: Intel Corporation 82850 850 (Tehama) Chipset AGP Bridge (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 04)
00:1f.0 ISA bridge: Intel Corporation 82801BA ISA Bridge (LPC) (rev 04)
00:1f.1 IDE interface: Intel Corporation 82801BA IDE U100 Controller (rev 04)
00:1f.2 USB Controller: Intel Corporation 82801BA/BAM USB Controller #1 (rev 04)
00:1f.3 SMBus: Intel Corporation 82801BA/BAM SMBus Controller (rev 04)
00:1f.4 USB Controller: Intel Corporation 82801BA/BAM USB Controller #1 (rev 04)
01:00.0 VGA compatible controller: nVidia Corporation NV11DDR [GeForce2 MX200] (rev b2)
02:09.0 Ethernet controller: ADMtek NC100 Network Everywhere Fast Ethernet 10/100 (rev 11)
02:0a.0 Ethernet controller: 3Com Corporation 3c905 100BaseTX [Boomerang]
02:0b.0 Ethernet controller: D-Link System Inc RTL8139 Ethernet (rev 10)
02:0d.0 Multimedia audio controller: Ensoniq ES1371 [AudioPCI-97] (rev 09)