Linux is a free Unix-type operating system originally created by Linus Torvalds with the assistance of developers around the world. Developed under the GNU General Public License , the source code for Linux is freely available to everyone.
show what is doing most disk accesses
CPU usage etc
I found sometimes 'reboot' and 'shutdown' don't work in virtual machines, in that case try:
#sync echo s > /proc/sysrq-trigger #optionally umount echo u > /proc/sysrq-trigger #reboot echo b > /proc/sysrq-trigger