Panic when trying to boot re-compiled Kernel

[Justin Wright]

Anybody,

I tried to install a BlueHeat RS485 card, on a XL-Class HP Workstation running Linux 7.1, that required me to re-compile the Kernel after patching. All was well until I tried to boot the new Kernel. During boot, it found the new Kernel, uncompressed it and started the boot process. About halfway through I got a Kernel Panic. I have included the last several messages that appeared on the screen:

request_module[block-major-8]: Root fs not mounted
VFS: Cannot open root device "811" or 08:11
Please append a correct "root=" boot option
Kernel panic: VFS: Unable to mount root fs on 08:11

The system at this point just hangs. I did verify that my lilo.conf file was correct and that I ran /sbin/lilo, so I know that is not the problem. The funny thing is, in my lilo.conf file I have root=/dev/sdb1 (which is what the default Kernel points to). I don't know where it is getting /dev/sdb11 from.

I then went back and tried to compile the original Kernel source code without the patches. In other words I just tried to rebuild the same default Kernel the system came with. The same exact result occurred which let me know it wasn't something with the BlueHeat Card. I then ran the recovery disk to get back to factory default status (i.e. RH 6.2 with the HP fx10 graphics driver) and tried from there with no luck.

After asking around work, it turns out that no one has ever been successful trying to run a re-compiled Kernel on these machines.

Has anyone else had this problem and/or know how to fix it?

Thanks.

Justin

[Bill Thorsteinson · Accepted solution]

Make sure you have all SCSI you need built into the
kernel. I haven't rebuilt a kernel for a long time
but the defaults I had didn't include any SCSI drivers.

You should start with the config file for the kernel
you installed, not the defaul IDE only kernel.
It should be with the kernel in the /boot directory.
Modify this and rebuild the kernel.

You want to have at least CONFIG_SCSI=y,
CONFIG_BLK_DEV_SD=y , and the appropriate driver
CONFIG_SCSI_????=y set in your config.

If you have a bootable rescue disk you should be
able to copy its kernel onto your drive until you
get the new kernel working.

You may have already done this. When rebuilding kernels rename the old kernel and add a lilo entry to
boot it. I make this the default until I am comforatble
with the new kernel.