I've seen this answer, and it doesn't work. (I've tried the following shortcuts: alt+ctrl+del|Esc|F2|Backspace,I've tried alt+ctrl+R,E,I,S,U,B under normal conditions and the system didn't respond so I doubt it will when the system freezes )
The freeze is apparently caused by Firefox 58.0.1 even though I didn't installed any extension
I'm using Ubuntu 16.04 looking for any shortcut to regain control of the system instead of rebooting every time this occurs (several times a day).
I appreciate your help
As @Byte Commander have pointed out the shortcut is rather alt+SysRq+R,E,I,S,U,B and it causes a hard reboot, then I'd like instead to have control over the system to issue a
kill command to the process causing the freeze.
B- however, this will do an (almost) hard reboot of your system. It's like holding the power button, just that it orders the kernel to flush all disk caches to prevent corrupt file systems.