Super shortcuts full#

There are some obvious security risks involved in fully enabling the SysRq key. If you want to try changing the SysRq settings for just your current session, you can run either sysctl kernel.sysrq=1 or echo '1' > /proc/sys/kernel/sysrq. Note that changing the setting through these methods will cause the changes to persist across reboots. If you want to make sure it will be enabled even before the partitions are mounted and in the initrd, then add sysrq_always_enabled=1 to your kernel parameters. Values greater than 1 can be used to selectively enable SysRq functions see the Linux kernel documentation for details.

Super shortcuts full#

To allow full use of the SysRq key on your system, add kernel.sysrq = 1 to your sysctl configuration. Systemd has the SysRq permissions bitmask set to 0x10 by default, which does not allow process signalling or rebooting, among other things. See Wikipedia:Magic SysRq key for more details. Whenever possible, it is recommended that you use these shortcuts instead of doing a hard shutdown (holding down the power button to completely power off the system). There are several low level shortcuts that are implemented in the kernel via the SysRq key which can be used for debugging and recovering from an unresponsive system.