The sysctl utility allows a Linux admin to query and modify kernel parameters in runtime. For example, to change the swappiness of a Linux system to 0, we can:
echo 0 > /proc/sys/vm/swappiness
Or we can use
sysctl -w vm.swappiness=0
To make the value persistent, Archwiki suggests to write
For persistent silent boot, Archwiki suggests to write
kernel.printk = 3 3 3 3 to
Similarly I have a
99-sysrq.conf on my system which works without the number as well.
Archwiki has a sysctl page which mentions the importance of the number:
Note: From version 207 and 21x, systemd only applies settings from
/usr/lib/sysctl.d/*.conf. If you had customized
/etc/sysctl.conf, you need to rename it as
/etc/sysctl.d/99-sysctl.conf. If you had e.g.
/etc/sysctl.d/foo, you need to rename it to
What does the number in
20-quiet-printk.conf denote here?