"Server command" setting in cvsroot setup, what does it do?

I'm trying to setup up a local cvsroot. The path is r:/cvs. Idea accepts this, but when you browse the repository, you don't see anything. I checkout out the project in a command line window, then tried using IDEA to add some new directories, and I get this error message from cvs that "server" is not a valid command.

I see in the cvsroot config dialog a field for "Server command" with a default value of "server". There is no help for this dialog. Anyone know what this does? And has anyone gotten a local repository to work reliably?