"echo c > /proc/sysrq-trigger" is hung in fedora14 guest os.

Hi, I am running Fedora14 in "Virtualbox 4.0.8". The host OS is Windows-XP. I configured kdump, kexec & crash as per instruction in Fedora-14-Deployment_Guide. The system gets hung and crash file is not generated after running the command "echo c > /proc/sysrq-trigger". ------------------------------------------------------ $ uname -a Linux fc14 2.6.35.6-45.fc14.i686 #1 SMP Mon Oct 18 23:56:17 UTC 2010 i686 i686 i386 $ service kdump status Kdump is operational $ su -c 'echo 1 > /proc/sys/kernel/sysrq' Password: $ su -c 'echo c > /proc/sysrq-trigger' Password: ------------------------------------------------------ Regards, Sudhakar.