Title: Manage ”nice” priority of daemons on OpenBSD
Author: Solène
Date: 11 September 2018
Tags: openbsd70 openbsd highlight
Description: 

Following 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.