Penrose provides a sample schema in PENROSE_SERVER_HOME/sample/schema called example.schema.
Copy this file to PENROSE_SERVER_HOME/schema/ext directory.
cd PENROSE_SERVER_HOME cp sample/schema/example.schema schema/ext
Compile the schema file. On Windows platforms execute:
bin\schema.bat schema\ext\example.schema
On Unix-like platforms execute:
bin/schema.sh schema/ext/example.schema
Restart the server.