Manage ”nice” priority of daemons on OpenBSD

Author: Solène

Date: 11 September 2018

Tags: openbsd70 openbsd highlight

NILFollowing a discussion on the OpenBSD mailing list *misc*, today I

will write about how to manage the priority (as in nice priority) of

your daemons or services.

In man page [rc(8)](http://man.openbsd.org/rc), one can read:

Before init(8) starts rc, it sets the process priority, umask, and

resource limits according to the “daemon” login class as described in

login.conf(5). It then starts rc and attempts to execute the sequence of

commands therein.

Using **/etc/login.conf** we can manage some limits for services and

daemon, using their rc script name.

For example, to make **jenkins** at lowest priority (so it doesn't

make troubles if it builds), using this line will set it to nice 20.

jenkins:priority=20

If you have a file **/etc/login.conf.db** you have to update it from

**/etc/login.conf** using the software `cap_mkdb`. This creates a

hashed database for faster information retrieval when this file is

big. By default, that file doesn't exist and you don't have to run

`cap_mkdb`. See [login.conf(5)](http://man.openbsd.org/login.conf) for

more informations.