Difference between revisions of "Kernel Panic"
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| − | You encounter a Kernel panic on boot up with an ASL kernel | + | You encounter a Kernel panic on boot up with an ASL kernel. |
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== Cause == | == Cause == | ||
Revision as of 16:21, 2 February 2011
Contents |
Overview
You encounter a Kernel panic on boot up with an ASL kernel.
Cause
This is almost always caused by a kernel design change. A module required for the system to see your disks is not being loaded in the initrd
Diagnostics
Send the output from cat /etc/modprobe.conf and lspci to support
Possible fixes (HARDWARE DEPENDENT)
Example modprobe.conf's from other systems
3ware Inc 9xxx-series SATA-RAID Intel Corporation 82801FB/FBM/FR/FW/FRW nVidia Corporation MCP51 IDE (rev f1) Symbios Logic 53c1030 (vmware)
Step 1) Update your modprobe.conf
vim /etc/modprobe.conf
Step 2) regenerate your initrd.img
/sbin/new-kernel-pkg --package kernel --mkinitrd --depmod --install 2.6.23.1-2.art
Step 3) Set the kernel to boot into your DEFAULT OS KERNEL. NOT THE ASL KERNEL. This is defined by the "default=" value, starting at 0 for the first position. This will set the system to fail "safe" back into the working kernel, without requiring you to power cycle or otherwise cold boot the system if there is a problem.
vim /etc/grub.conf
example:
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/md0
# initrd /initrd-version.img
#boot=/dev/sda1
default=1
timeout=5
serial --unit=0 --speed=57600
terminal --timeout=5 serial console
title CentOS (2.6.23.1-3.art)
root (hd0,0)
kernel /vmlinuz-2.6.23.1-3.art ro root=/dev/md0 console=tty0 console=ttyS0,57600n8 selinux=0 noapic
initrd /initrd-2.6.23.1-3.art.img
title CentOS (2.6.9-42.0.10.EL)
root (hd0,0)
kernel /vmlinuz-2.6.9-42.0.10.EL ro root=/dev/md0 console=tty0 console=ttyS0,57600n8
initrd /initrd-2.6.9-42.0.10.EL.img
Step 4) Set the "panic" flag on the ASL kernel line
title CentOS (2.6.23.1-3.art)
root (hd0,0)
kernel /vmlinuz-2.6.23.1-3.art ro root=/dev/md0 console=tty0 console=ttyS0,57600n8 selinux=0 panic=5
initrd /initrd-2.6.23.1-3.art.img
Step 5) Set the ASL kernel to boot once, with the grub command
[root@www2 ~]# grub
grub> savedefault --default=0 --once grub> quit
Step 6) Reboot
