Another systemd annoyance

[Joonas Sarajärvi]

2015-01-31 13:52 GMT+02:00 Heinz Diehl <htd+ml at fritha.org>:
> Hi,
>
> tried to safely bring down a crashed Fedora 21 machine today, but M-sysrq
> didn't do anything. After bringing the machine up again, the logs showed
> that M-sysrq functionality was disabled. After investigating further, it seemed
> that only Sysrq-S (emergency save) was actually working. In /etc/sysctl.d/01-sysctl.conf,
> "kernel.sysrq=1" was present. It took me nearly 30 min. to find out that systemd
> has it's own sysctl definitions, gladly ignoring/overwriting /etc/sysctl.d. In
> /usr/lib/sysctl.d/50-default.conf, "kernel.sysrq=16" was set, which is what crippled
> full sysrq functionality.
>
> In addition, I'm curious what happens when the next systemd update gets pulled in.
> Most probably, my manual settings will be overwritten with what systemd thinks
> is good for the user..
>

Processing order of files under /etc/sysctl.d/ seems to be such that
files with a high number override files with a low number. If you do
not want your changes to be overridden, I think it would be a good
idea to pick a high number like 90 instead of 01 for the start if your
config file name.

-Joonas