[SOLVED] How do I recover from Kernel Panic?

jfraymondpa · 06-17-2011, 06:51 PM

My desktop hung during an update of my Fedora 14 kernel. When I rebooted I got a Kernel Panic on the new kernel (91). Rebooted, went into GRUB and switched to the older kernel (90) and still got a Kernel Panic.

I'm stumped on what to do to get back short of a reinstall, which will cause a loss of data (My last backup is a month old).

I've tried to use "sysrescue" which boots ok and I can see the LV but can't figure how to access them so as to move the data from the /home/john directory out to a USB drive.

Help Please,
John

phil.d.g · 06-17-2011, 07:29 PM

First of all:

Boot a live cd and mount your system at /mmt:

Code:

# vgchange -a y
# mount /dev/mapper/VolGroup00-LogVol00 /mnt
# for d in dev proc sys; do mount --bind /$d /mnt/$d; done
# chroot /mnt
# mount -a
#

Then your system will be reasonably usable. You will have to adjust the commands to suit your own env.

Now, perform your backup!!!

Exit the chroot, unmount the partitions and perform fsck on each of them. Then remount the partitions, enter the chroot and try to upgrade kernel again.

jfraymondpa · 06-18-2011, 09:33 AM

Quote:

Originally Posted by phil.d.g

First of all:

Boot a live cd and mount your system at /mmt:
...

Thanks for the instructions Phil,
One question, how do I get to a command line when booting a live cd?
I've tried all ways but can't find the key to the command line.

-- John

MTK358 · 06-18-2011, 09:34 AM

Try Ctrl+Alt+F2.

A GUI terminal will work just fine, though.

jfraymondpa · 06-22-2011, 07:51 PM

Thanks Phil and MTK358,
My mistake in booting the Live CDs was trying to get to the command line from the start, not letting it boot all the way.
Phil your instructions worked to get me going. Need to do: su - to get to root from "liveuser" and then the vgchange and the mount didn't need the rest. Have gotten all the data I need backed up.
Now if I can solve my system hang problem I'll be back in clover.

Thanks again,
John

phil.d.g · 06-23-2011, 03:18 AM

The rest will drop you in your own local installation environment, from there you can use your distro's package manager, complete the upgrade, rebuild initrds, etc to fix your problems.