kernel panic

[Karl Larsen]

Les Mikesell wrote:
> Karl Larsen wrote:
>> Les Mikesell wrote:
>>> Karl Larsen wrote:
>>>> Les Mikesell wrote:
>>>>> Karl Larsen wrote:
>>>>>>    I found this on Google but it doesn't help me much:
>>>>>>
>>>>>> echo "Loading scsi_mod module"
>>>>>> insmod /lib/scsi_mod.o echo "Loading sd_mod module"
>>>>>> insmod /lib/sd_mod.o echo "Loading cpqarray module"
>>>>>> insmod /lib/cpqarray.o echo "Loading jbd module"
>>>>>> insmod /lib/jbd.o echo "Loading ext3 module"
>>>>>> insmod /lib/ext3.o mount -t proc /proc /proc
>>>>>> echo Mounting /proc filesystem
>>>>>> echo Creating root device
>>>>>> mkrootdev /dev/root
>>>>>>
>>>>>> This seems to be where /dev/root comes from. And my kernel can't 
>>>>>> find it for some reason.
>>>>>>
>>>>>>
>>>>>>
>>>>>> echo 0x0100 > /proc/sys/kernel/real-root-dev
>>>>>> umount /proc
>>>>>> echo Mounting root filesystem
>>>>>> mount --ro -t ext3 /dev/root /sysroot
>>>>>> pivot_root /sysroot /sysroot/initrd
>>>>>
>>>>> There is a point in the boot sequence where the bios-loaded kernel 
>>>>> trades the initrd RAM disk image (also bios loaded) for the real 
>>>>> root partion mount point.  Several things can go wrong here. Grub 
>>>>> may have told the kernel to look in the wrong place for the root 
>>>>> file system, the file system might be unreadable, or you may have 
>>>>> moved the system onto a machine with a different type of disk 
>>>>> controller that needs a different driver module included on the 
>>>>> initrd.  The main reason you need the initrd is to load drivers 
>>>>> for the root filesystem if they aren't compiled into the kernel 
>>>>> but it will only include ones for the the machine where the system 
>>>>> was originally installed. If you can access the disk, somewhere in 
>>>>> the boot messages you should see it detecting the device and 
>>>>> partitions.  If you don't see that, the kernel can't see the disk 
>>>>> and you'll have to rebuild the initrd with the right module.
>>>>>
>>>>    Initrd has to be the problem Les. I have had the old hard drive 
>>>> on this new box and I was surprised that FC6 would boot up but F7 
>>>> did what it has done all along. Now I did load a new F7 on the old 
>>>> hard drive and it booted up fine. So this info backs up my belief 
>>>> that initrd is the problem.
>>>>
>>>>    I will now try and find out HowTo rebuild initrd from a Rescue 
>>>> cd :-)
>>>
>>> If your rescue boot mounts the system drives and suggests a chroot 
>>> command, do that, then add the right alias command to 
>>> /etc/modprobe.conf (will depend on hardware) and then run mkinitrd.
>>>
>>    What is an alias command? How do I find it with a rescue cd?
>
> If you have a working install for this disk controller, look in 
> /etc/modprobe.conf to see what the line should be.  Here's a sample 
> modprobe.conf from a machine with an intel NIC and 2 different scsi 
> controllers:
> # cat modprobe.conf
> alias eth0 e1000
> alias scsi_hostadapter mptscsibase
> alias scsi_hostadapter1 mptscsih
> alias scsi_hostadapter2 aic7xxx
>
> But the modules need to match your exact hardware.  If you have a 
> normal  old IDE controller, you shouldn't need this to boot.
>
> If you boot the install CD/DVD with 'linux rescue' at the command 
> prompt and your fstab file is correct, it should mount the system 
> partitions for you and suggest a chroot command for troubleshooting.  
> After you do the chroot, you'll have all the installed system 
> facilities at your disposal to edit the /etc/modprobe.conf file and 
> run mkinitrd, including the man pages.  When you are done, type exit 
> twice to unmount cleanly and reboot (once for the chroot shell, once 
> for the rescue shell).  If the rescue mode boot doesn't mount the 
> partitions for you, then you have some other problem to fix first.
>
    Thanks Les, I printed this email and will spend time doing it right. 
I have just a standard IDE controller so expect to see nothing.



-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.