When I try to start rails s, I get an error like this ...
$ rails s -b 0.0.0.0 => Booting Puma => Rails 184.108.40.206 application starting in development => Run `rails server -h` for more startup options A server is already running. Check /Directory path/tmp/pids/server.pid. Exiting
This is an error that occurs because the server is already running.
Execute the following command.
$ lsof -i:3000 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME ruby2.5 3033 vagrant 16u IPv4 27499 0t0 TCP *:3000 (LISTEN)
Delete the above PID value with the following value.
$ kill -9 3033
This will solve it.