Description
   initlocation 
   creates a new PostgreSQL secondary database storage area.
   See the discussion under CREATE DATABASE
   about how to manage and use secondary storage areas. If the argument does not contain
   a slash and is not valid as a path, it is assumed to be an environment variable,
   which is referenced. See the examples at the end.
  
   In order to use this command you must be logged in (using su, for example)
   as the database superuser.
  
Examples
    To create a database in an alternate location, using an
    environment variable:
$ export PGDATA2=/opt/postgres/data
    Stop and start postmaster so it sees the PGDATA2
    environment variable.  The system must be configured so the
    postmaster sees PGDATA2 every time it starts.  Finally:
$ initlocation PGDATA2
$ createdb -D PGDATA2 testdb
   
    Alternatively, if you allow absolute paths you could write:
$ initlocation /opt/postgres/data
$ createdb -D /opt/postgres/data/testdb testdb