Should custom sysctl settings go in sysctl.conf or sysctl.conf.local?

[zoltan]

Hello,
I looked at the sysctl.conf manual, and this is what it says:

/etc/sysctl.conf          Initial settings for sysctl(8).
/etc/sysctl.conf.local    Machine-specific settings for sites with a common /etc/sysctl.conf.

I'm not sure if I understood correctly. If I have custom configurations, is it recommended to use the sysctl.conf.local instead of sysctl.conf ? I think the advantage here is that if I put settings in sysctl.conf.local, they won't be accidentally overwritten by an update or something similar, right? I also checked the "Absolute FreeBSD" book but couldn't find any information about the .local file, the author just mentions the sysctl.conf.

 

[cracauer@]

The difference comes into play if you have multiple machines that are configured in a similar way. You put the common statements in sysctl.com and copy that file around. Statements for a single machine are in local.

 

[Kai Burghardt]

The sysctl.conf.local option exists for deployments that have a network‑wide shared sysctl.conf, cmp. PR 254901.​

• /etc/rc.d/sysctl processes /etc/sysctl.conf first, /etc/sysctl.conf.local second. Should you want to override some values from your globally shared sysctl.conf on one machine, define the overrides in sysctl.conf.local. Note that this obviously creates a time window when some undesired sysctl(8) settings are in effect.​
• Furthermore, a freebsd-update(8) won’t bother you with a merge conflict if you edit /etc/sysctl.conf.local since /etc/sysctl.conf.local is not (and will not be) distributed.​

My recommendation is: Use /etc/sysctl.conf. More files correlates to more complexity (case in point: your question). Unless you can justify that added complexity – i. e. the intended use case of network‑wide shared sysctl.conf vs. some local deviations – don’t use it (don’t use sysctl.conf.local).​