unable to find device-mapper major/minor? help!!!!! can't boot up! kernel panic!

newtovanilla · 11-22-2008, 11:26 PM

this is a kinda several part question, from a Linux newbie with a kernel panic issue! Can't boot! Need help...

Linux 2.6.22
When I try to boot, the boot screen freezes at the point of a "kernel panic", and the message just before the kernel panic is "unable to find device-mapper major/minor". What does that mean, and how do I fix it to get the Linux kernel to boot?

I tried searching google for this error, and could not find the solution to it. And, is there a way to scroll up the boot message screen to see what other boot messages there are? The screen seems stuck.

pinniped · 11-22-2008, 11:40 PM

Are you booting via an initramfs (initrd) image or booting the kernel directly into the final filesystem?

newtovanilla · 11-22-2008, 11:44 PM

Quote:

initramfs (initrd) image

Booting with GRUB and an initrd. What is booting the kernel directly into the filesystem?

pinniped · 11-23-2008, 12:55 AM

OK, what was your older version of kernel?

If you have all the necessary drivers built into the kernel, you can boot without creating the initramfs image - this results in directly mounting the final filesystem without going through a temporary filesystem (initramfs).

newtovanilla · 11-23-2008, 02:17 PM

Quote:

OK, what was your older version of kernel?

Same version. There was no upgrade to the kernel, still 2.6.22 Linux. I am using an initrd and GRUB. I moved the Linux installation from a SATA harddrive to a PATA harddrive. What driver is needed for PATA? The initrd has most of the SATA drivers already. Is that the problem that is causing the "kernel panic"?

onebuck · 11-23-2008, 02:39 PM

Hi,

Yes, that's your problem. You changed the device so you must create a initrd that reflects that new device.

You can use a livecd or install cd to boot the system;

After you get to the login then from the cli (command line);

Code:

~#mkdir /Your_temp                   #temporary mount point
~#mount /dev/your_device /Your_temp  #this is the device you installed to
~#chroot /Your_temp                  #change to yours
~#cd /Your_temp/boot                 #change to directory with initrd
                                     #create your initrd with proper options for your system
~#cd /Your_temp/etc                  #to edit your lilo.conf
~#vi lilo.conf                       #edit lilo.conf, if need be
~#lilo -v -t -b /dev/your_device     #sda, hda this will only test 
~#lilo -v -b /dev/your_device        #this will write MBR to your_device

I assumed you are using lilo if grub then edit your 'menu.lst' which is the configuration file for grub.

You should now be able to re-boot your system.

BTW, You should be able to pause or view as you go.