Lost with volumes


I am confused. When I started with docker containers I thought
in docker run command a -v /folderhost:/foldercontainer

will give me the chance to share files between host//container.
I thought to remember me that it was working in both directions.
E.G. a container created a log file in foldercontiner this is to be found in folderhost.

But now I tried Mosquitto original container
with this command:
docker run --name mqtt -it
-p 1883:1883 -p 9001:9001
-v /docker/config/mosquitto:/mosquitto/config
-v /docker/config/mosquitto/data:/mosquitto/data
-v /docker/config/mosquitto/log:/mosquitto/log

but while start it is showing errors in lod file. It can not find conf files.

Is it only working in one direction? host->container

How can I get the other way?