Another systemd annoyance

[Ahmad Samir]

On 31 January 2015 at 14:01, Joonas Sarajärvi <muep at iki.fi> wrote:
> 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

Exactly.
$ cat /etc/sysctl.d/99-sysctl.conf
# sysctl settings are defined through files in
# /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/.
#
# Vendors settings live in /usr/lib/sysctl.d/.
# To override a whole file, create a new file with the same in
# /etc/sysctl.d/ and put new settings there. To override
# only specific settings, add a file with a lexically later
# name in /etc/sysctl.d/ and put new settings there.
#
# For more information, see sysctl.conf(5) and sysctl.d(5).

I use an /etc/sysctl.d/99-custom-sysctl.conf to override stuff from
/usr/lib/sysctl.d/ .

--
Ahmad Samir