PostgreSQL set PGDATA variable

Question

Server: Ubuntu server 14 lts + PostgreSQL 9.2 I want create cluster database using drbd, but i can't set PGDATA without cluster initialization. I just need say pgsql use data from drbd disk. How i can do it?

Example 1:

mkdir /cluster/var/lib/pgsql -p
chown postgres:postgres /cluster/var/lib/pgsql -R
cp -R /var/lib/pgsql /cluster/var/lib/pgsql

edit /etc/init.d/postgresql :
 PGDATA=/cluster/var/lib/pgsql/data
...
PGLOG=/cluster/var/lib/pgsql/pgstartup.log

/etc/init.d/postgresql start

in postgresql 8.3 it works, but in 9.2 i can't change pgdata in /etc/init.d/postgresql, i need find another file and set pgdata, but, surprise, it's do nothing.

Example 2: PGDATA - Specifies the directory where the database cluster is to be stored; can be overridden using the -D option.

Ok, let's start: --pgdata=directory yeah, it's works! but now we have postgresql-xc and error like "postgresql don't know this user - postgresql". drbd start replicate data from cluster, but postgresql start it too.

UPD 1:

root: initdb --pgdata=/home/username/dir
~initdb not install~bla-bla-bla~use apt-get install postgres-xc

UPD2:

$: /usr/lib/postgresql/9.3/bin/initdb --pgdata=/whateveryouwant

#now you can run postgresql only one way:

$: /usr/lib/postgresql/9.3/bin/postgres -D /see_up

#then:

LOG:  database system was shut down at 2014-09-26 15:56:33 YEKT   
LOG:  database system is ready to accept connections    
LOG:  autovacuum launcher started

#aaaaaaaaaaand...nothing. just empty console, ^C stopping postgres    
#another SSH connect:

$: ps-ela

S  1000  5995  5217  0  80   0 - 62202 poll_s pts/0    00:00:00 postgres    
1 S  1000  5997  5995  0  80   0 - 62202 poll_s ?        00:00:00 postgres    
1 S  1000  5998  5995  0  80   0 - 62202 poll_s ?        00:00:00 postgres    
1 S  1000  5999  5995  0  80   0 - 62202 poll_s ?        00:00:00 postgres    
1 S  1000  6000  5995  0  80   0 - 62415 poll_s ?        00:00:00 postgres    
1 S  1000  6001  5995  0  80   0 - 26121 poll_s ?        00:00:00 postgres

#is it ok? because...

$: /etc/init.d/postgresql status    
9.3/main (port 5432): down

Answer 1

Place the below in your ~/.bashrc file.

PATH=$PATH:/usr/lib/postgresql/<PostgresVersionNumber>/bin
export PATH
export PGDATA="$HOME/<FolderNameForPostgresDatabases>"

Replace 'PostgresVersionNumber' with your installed Postgres version number.
Replace 'FolderNameForPostgresDatabases' with the name of the folder you want your postgres databases to reside. Make sure the folder is created

From a terminal, you have to navigate to ~/FolderNameForPostgresDatabases, then run:

initdb

Do that before trying to run:

pg_ctl start