**Magic of SysReq**

Before you reach for the reset or power off button.

#linux #tips_and_tricks #sysreq

By holding down the `Alt` and `SysReq` (`PrtScr`) keys and pressing specific letter keys, you can send commands directly to the kernel. Since the kernel listens to these commands directly, they will work even if the `X server` is completely blocked and not responding to keyboard input.

“r” - to reset the keyboard.

“e” - to send a `TERM` signal to all processes.

“i” - send a `KILL` signal to all remaining processes, forcing them to terminate.

“s” is a call to kernel synchronization, all buffers will be flushed to disk to correctly close the remaining open files.

“u” - unmount all file systems and remount them in read-only mode to avoid further data corruption.

“b” - reboot the system.

That is, press and hold `Alt` and `SysReq`, then press `REISUB` in turn, waiting a couple of seconds between each pressing.