I'm running Ubuntu 12.04 on AWS/EC2 and having a large number of hosts going belly up. I'm trying to enable kernel dumping, but when I simulate a kernel panic, there's no .crash file written anywhere on the file system.
I followed the instructions here: https://wiki.ubuntu.com/Kernel/CrashdumpRecipe
And things seem set up correctly:
# cat /proc/cmdline
root=LABEL=cloudimg-rootfs ro console=hvc0 crashkernel=384M-2G:64M,2G-:128M
# dmesg |grep crash
[ 0.000000] Command line: root=LABEL=cloudimg-rootfs ro console=hvc0 crashkernel=384M-2G:64M,2G-:128M
[ 0.000000] Reserving 64MB of memory at 832MB for crashkernel (System RAM: 1708MB)
[ 0.000000] Kernel command line: root=LABEL=cloudimg-rootfs ro console=hvc0 crashkernel=384M-2G:64M,2G-:128M
# cat /sys/kernel/kexec_crash_loaded
1
But when I execute:
# echo c | sudo tee /proc/sysrq-trigger
The system reboots as expected, but no 'crash' file of any kind is generated. What might I be doing wrong?
/var/log/messages
?