I already have a local server running with data in the default 5432 port in pgAdmin. I need to create a different local host server to test importing another DB group.
But when I try to create one more server in localhost:5400, I get the following error
Internal server error: unable to connect to server connection to server at "localhost". Port 5400 failed: connection refused to server at "localhost". Is the server running on that host and accepting tcp/ip connections?
But if I use the same port, a serer with all the same data is getting created which may conflict with the import and also confuse me. So I need a totally new server without these data in it.
My guess is what you think is creating a server in pgAdmin is really just creating a connection to a server. That would mean it lets you create a connection to a server you already have on 5432 as many times as you wish (note that's multiple connections to the exact same one), but since there's nothing running on 5400, it fails to connect there, and it doesn't attempt to create one.
I don't think pgAdmin lets you install a whole new server/cluster/instance. You can create new databases on the one you already have connected to with CREATE DATABASE, but to install a whole new separate server on a different port, you just need to go through the regular install process.
If you were the one to set up the PostgreSQL server currently running on your port 5432, you can probably repeat the process and just select a different port.