Starting multiple HomeBrew Services I would like to run two different mongodb databases on my Mac. I installed mongodb with the HomeBrew manager. However I was unable to find a possibility to create new homebrew services. I already created the new config file and new location to store the data. 

Cheers
First, you are not able to use brew service to start the two different mongodb. Cause the LaunchAgent .plist files have the same name. The former enable one will be overwritten by the latter one. Find the corresponding .plist service file, copy it to ~/Library/LaunchAgents as a different name.

Secondly, the service .plist must be modified to use a different conf for mongodb. It's impossible to make two daemons listen on the same port.