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), 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.
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) for