Rrdcached setup clarification on Centos7

Please could you clarifiy these bits of the rrdcached setup?

Enable this to use rrdcached. Be sure rrd_dir is within the rrdcached dir

and that your web server has permission to talk to rrdcached.

  1. not sure where this directories are? I have an /opt/librenms/rrd with serverX folders
  2. file permissions on /run/rrdcached.sock ? These are

srwxrw----. 1 root librenms 0 Jun 14 12:52 rrdcached.sock
-rw-r–r--. 1 root root 6 Jun 14 12:52 rrdcached.pid

I have the rrdcached service up and running on Centos7.6
RRDcached/RRDtool version = 1.4.8

The monitoring system has been up with a few hosts for about a month, but I’m looking to enable rrdcached and verify it is working, before adding more hosts.