Troubleshooting

Keep track of:
– system hardware
– installation of O.S
– HW and SW additions
– anomalies
Kernel Panics

  • What? a problem occurs that is so serious that kernel stops systems
  • When? typically during boot – with boot message -what the message say  – dmesg command
  • How to diagnose? Start with boot messages , LKCD

LKCD  Linux Kernel Crash Dump

  • Install from source or RPM, patch and install new kernel
  • Panic results in LKCD dumping RAM to disk (core dump)

Test LKCD

#define __KERNEL__
#MODULE

#include init_module(void)

int init_module(void)
{
panic (“panic has been called”);
return[];
}

#compare the program with cc command
cc -c -l /usr/linux/include panic.c
insmod panic.o  # create a kernel on the system

Run lcrash
parameters :

  • sys map file
  • dump image
  • kerntypes

lcrash /boot/System.map /dump.1 /boot/Kerntypes