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Re: boot failure

Dan Davison wrote:


Any help with the following would be much appreciated: I was attempting to
update a kernel from 2.2.20 to 2.6.8 and it seems now that neither of the
kernel links in the lilo menu will boot. Both exit with the same kernel
panic message and the output up to that point appears to be identical.
This output makes mention of NTFS drivers, ACPI, powerNOW and other things
that I believe mean I'm looking at output from the 2.6.8 kernel. I think
I've somehow managed to point both the links in lilo at the new kernel. Is
there anything that can be done, short of reinstalling debian from CD (and
presumably losing all data that way?)
Yes, you can recover without reinstalling, but sometimes it's hard to diagnose remotely.
Also, as an aside, if you have separate partitions for your /home (and possibly others), a reinstallation doesn't hurt you so bad. If it comes down to a reinstall and you don't have a separate partition for /home, you can boot off a Knoppix CD and backup your data to a network share, USB device, CD-ROM, etc. 


The exit error message is (after some stuff mentioning ACPI) :
....
VFS: Cannot open root device "305" or unknown-block(3,5)
Please append a correct "root=" boot option
Kernel panic: VFS: Unable to mount root fs on unknown-block(3,5)

More details:

I obtained 2.6.8 kernel source via apt-get and included support for EXT3
filesystem, changed the processor type to AMD Athlon, NTFS support, SCSI
emulation, ACPI and processor clock scaling in menuconfig. I made a .deb
with make-kpkg and installed it with dpkg -i. I answered yes to the
question resulting from dpkg -i about making modifications to lilo so that
the new kernel would be available to boot. After this I checked that
/vmlinuz was pointing at the new kernel and looked at /etc/lilo.conf. The
"label" for the stanza associated with the /vmlinuz link said
"Linux_2.6.6" (a previous kernel installation failure)
This makes me think the installation of your new kernel was not properly completed for some reason. 


and I changed the
text of the label to "linux_2.6.8", but nothing else in /etc/lilo.conf.
After this modification to /etc/lilo.conf I ran lilo, which added the
various boot options OK, but produced a warning message that I did not
understand containing the word block and some memory addresses. Since I
believed that the old 2.2.20 link would be OK to boot, I proceeded to
power down and try to boot the new kernel, with the above-described
failure.

This is on an HP Athlon laptop.
I believe what I would do is boot off a Knoppix CD (or similar) and manually mount the / directory rw (as necessary), redo the symlinks to get /vmlinuz to point to your older working 2.2 kernel, reconfigure /etc/lilo.conf accordingly, then run "chroot /whereverrootismounted", run "lilo", "exit", and "reboot". Hopefully this will give you a working 2.2 system, from whence you can repair what's wrong with your 2.6 kernel and try again. 

--
Kent
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