Administración de PostgreSQL
initdb - Ejemplo

$ whoami
postgres
$ initdb -D /usr/local/alvh/pgsql
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

creating directory /usr/local/alvh/pgsql/data... ok
creating directory /usr/local/alvh/pgsql/data/base... ok
creating directory /usr/local/alvh/pgsql/data/global... ok
creating directory /usr/local/alvh/pgsql/data/pg_xlog... ok
creating directory /usr/local/alvh/pgsql/data/pg_clog... ok
creating template1 database in /usr/local/alvh/pgsql/data/base/1... ok
creating configuration files... ok
initializing pg_shadow... ok
enabling unlimited row size for system tables... ok
creating system views... ok
loading pg_description... ok
vacuuming database template1... ok
copying template1 to template0... ok

Success. You can now start the database server using:
/usr/local/alvh/pgsql/bin/postmaster -D /usr/local/alvh/pgsql/data
or
/usr/local/alvh/pgsql/bin/pg_ctl -D /usr/local/alvh/pgsql/data -l logfile start