CentOS

Hi,
is DefaultTimeoutStartSec related to every systemd unit?
I am asking this because generally during boot I notice some process hung and the timer says: xx seconds / 90 seconds (the default settings).
Today I saw a similar behavior with rc.local but the timer reported xx seconds / no limit.

So my question is: if I set DefaultTimeoutStartSec to 15 seconds (for example), is this configuration valid for every unit?
rc.local is handled by other settings?
Thank you!

man systemd-system.conf then search for DefaultTimeoutStartSec= and page backwards to the start of the section

A good starting point for most systemd/systemctl parameters is to read man systemd.directives and search that for the thing you're interested in. That then shows you which systemd man page the detail of the parameter can be found in.