This is a weird situation which I found myself in recently. One of the ubuntu servers were having issues and was unable to launch any process for unknown reason (kernel issue/disk or filesystem failure/etc). Puzzled, I tried to reboot the machine using
reboot, but the system did not allow me to. It also failed to run utilities such as
After some googling, here is the magic (“magic SysRq key”):
echo 1 >/proc/sys/kernel/sysrq echo s > /proc/sysrq-trigger (optional, sync mounted filesystems) echo u > /proc/sysrq-trigger (optional, remount filesystems as read-only) echo b > /proc/sysrq-trigger
echo is a bash shell builtin command and does not have to be a new process. Reboot now!