postgresql questions

Hello everybody,

I have some questions on Postgresql, pls help me if you can.

I have installed postgresql 6.2.1on FreeBSD 2.2.6. To start it, I must
first start the postmaster running, so I :

1) su pgsql (this account I think was created during the installation)

2) postmaster
(I get this message :"postmaster does not know where to find the
database system data. you must specify the directory that contains the
database system either by specifying the -D invocation option or by
setting the PGDATA environment variable". )

Then I try
3)postmaster -D /usr/local/pgsql/data
and it runs, I wonder why it don't start automatically when I start the
server, my /usr/local/pgsql/.profile file had defined the PGDATA as
/usr/local/pgsql/data and I have the file /usr/local/etc/rc.d/pgsql.sh .

4) when I run "psql template1 " or "createdb test" I get the following:

connection to database 'template1' failed.
PQexec() -- Request was sent to backend, but backend closed the channel
before responding. This probably means the backend terminated abnormally
before or while processing the request.
freebsd /kernel : cmd postgres pid 782 tried to use non-present SYSVSEM
freebsd /kernel : cmd postgres pid 782 tried to use non-present SYSVSEM
freebsd /kernel : cmd postgres pid 755 tried to use non-present SYSVSEM
freebsd /kernel : cmd postgres pid 755 tried to use non-present SYSVSEM

createdb: database creation failed on test.
[1] 755 Bad system call (core dumped) postmaster -D/usr/local/pgsql/data

And the postgresql stops. Can anyone help me on this please?

Best Regards,

chan