[systemd-devel] Bind key combination to isolate emergency mode

Lennart Poettering lennart at poettering.net
Mon Jun 22 12:16:06 PDT 2015

On Sat, 20.06.15 17:35, Thomas Meyer (thomas at m3y3r.de) wrote:

> > Also don't forget the magic SysRq keys – Alt+SysRq+F will run the OOM 
> > killer in case of heavy swapping, Alt+SysRq+E/I will sigterm/sigkill 
> > all programs (systemd will restart gettys afterwards), and 
> > Alt+SysRq+N will renice high-priority processes. You need to enable 
> > this via sysctl.conf though.
> Hi Mantas,
> thanks for the hint. I will try this.
> I remember that SysRq was once always enabled? It now seems to be
> disabled in current Fedora releases. I think enabling F key should be
> default. At least it shouldn't be possbile to do something bad with it,
> or is it?

well, it's an authenticated way to execute quite a few operations that
are potentially risky, hence it's disabled by default.

Executing potentially risky operations is fine, but only after auth.


Lennart Poettering, Red Hat

More information about the systemd-devel mailing list