Postgresql 9.3 on Centos 7 with custom PGDATA

You need to create a custom postgresql.service file in /etc/systemd/system/, which overrides the default PGDATA environment variable. Your custom service file can .include the default postgresql service file, so you only need to add what you want to change. That way, upgrades can still modify/improve? stuff in the default service file, while your change is preserved.

This is how I just did it in Centos 7:

cat <<END >/etc/systemd/system/postgresql.service
.include /lib/systemd/system/postgresql.service
[Service]
Environment=PGDATA=/mnt/postgres/data ## <== SET THIS TO YOUR WANTED $PGDATA
END

systemctl daemon-reload

systemctl restart postgresql.service

Verify :

ps -ax | grep [p]ostgres

Update:

Rather than manually creating the file and adding the .include line, you can also use the systemd built-in way:

systemctl edit postgresql.service

This will open your default editor and save your changes to /etc/systemd/system/postgresql.service.d/override.conf

I think the most "CentOS 7 way" to do it is to copy the service file:

sudo cp /usr/lib/systemd/system/postgresql-9.6.service /etc/systemd/system/postgresql-9.6.service

Then edit the file /etc/systemd/system/postgresql-9.6.service:

# Location of database directory
Environment=PGDATA=/mnt/volume/var/lib/pgsql/9.6/data/

Then start it sudo systemctl start postgresql-9.6 and verify:

# sudo ps -ax | grep postmaster
32100 ?        Ss     0:00 /usr/pgsql-9.6/bin/postmaster -D /mnt/volume/var/lib/pgsql/9.6/data/

try this:

 ## Login with postgres user
 su - postgres
 export PGDATA=/your_path/data
 pg_ctl -D $PGDATA start &

It appears the real problem was setting the environment variables, which I got working in the following thread: Centos 7 environment variables for Postgres service The issue is the PGDATA variable set inside the custom /etc/systemd/system/postgresql-9.3.service which should be created from the contents of /usr/lib/systemd/system/postgresql-9.3.service which uses the default PGDATA var.