ROOT @SHUTDOWN

Usage: @SHUTDOWN <reason>

This command will shut down services. First it will flush the database to disk. The command /servstart will restart services.

Example:
/msg operserv @shutdown Services will be back shortly.

You can bring services back up by connecting to the server that holds services. Or you can restart your server with /restart and it will restart with services connected, but this will toss everyone off the server while it restarts, and cause splits if there are other servers linked to yours. The easiest way to get services back is probably the /servstart command. See servstart in the Services Administrators Server Commands section.