Some time ago i noticed huge corruption on / on one of my servers, /sbin/reboot was gone also with /sbin/init, /sbin/poweroff and so on.
How to shutdown machine remotley ? Simple:
echo 1 > /proc/sys/kernel/sysrq
echo o > /proc/sysrq-trigger
( this requires SysRQ compiled in kernel, most distributions have this
compiled in their’s kernels )