Magic SysRQ

Activate

temporary

echo 1 | sudo tee /proc/sys/kernel/sysrq

permanent

cat /etc/sysctl.d/10-magic-sysrq.conf

#
# In general, the magic SysRq key is not needed for the average Ubuntu
# system, and having it enabled by default can lead to security issues on
# the console such as being able to dump memory or to kill arbitrary
# processes including the running screen lock.
#
# Here is the list of possible values:
#   0 - disable sysrq completely
#   1 - enable all functions of sysrq
#  >1 - enable certain functions by adding up the following values:
#          2 - enable control of console logging level
#          4 - enable control of keyboard (SAK, unraw)
#          8 - enable debugging dumps of processes etc.
#         16 - enable sync command
#         32 - enable remount read-only
#         64 - enable signalling of processes (term, kill, oom-kill)
#        128 - allow reboot/poweroff
#        256 - allow nicing of all RT tasks
#
#   For example, to enable both control of console logging level and
#   debugging dumps of processes: kernel.sysrq = 10
#
kernel.sysrq = 176

kernel.sysrq = 1

On Sony VAIO

Fn + Alt + S-Abf