moving postgresql.conf: pg_ctl can't find postmaster.pid anymore

Hi,

The Postgresql configuration files can be kept elsewhere than the data
directory, as is described in the section about "File Locations."
(18.2 of as of 8.4)[1]

The documentation here basically mentions two ways of doing this.

First you can start Postgresql with the -D option to pg_ctl pointing to
the configuration files(/etc/postgresql for example), and then specify
the data cluster directory (/var/postgresql/data for example) inside
postgresql.conf.

$ pg_ctl -D /etc/postgresql -l .../logfile start

The second way is starting postgresql with the `config_file` parameter
passed to the postgres process via the -c option of the postgres
command, then specify each file individually inside postgresql.conf.

$ pg_ctl -o "-c config_file='/etc/postgresql/postgresql.conf'" \
    -l .../logfile  start

Both methods works fine on server startup, but the first method gives
problems when stopping the server with pg_ctl.

The problem I found is that pg_ctl expected the file 'postmaster.pid'
inside the configuration directory passed to with -D (/etc/postgresql),
but postgres created it in the data cluster directory as specified
inside postgresql.conf (/var/postgresql/data).

I could fake pg_ctl with -D pointing to the data cluster
directory, not to the configuration directory. Then it worked fine. But
I feel this is not the right way of doing things.

As I understand, `external_pid_file`, has nothing to do with this: it is
an *extra* pid file, not the one needed by pg_ctl.

Any comments on this are very welcome.

Thank you all and have a very nice day/night :)

Ludo

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[1]
http://www.postgresql.org/docs/8.4/static/runtime-config-file-locations.html