How do I install PostgreSQL in Debian/Ubuntu? I'm following these instructions, however I can only get to step 17.2.

Despite installing postgresql successfully via the  

sudo apt-get install postgresql


command, upon running

initdb -D /usr/local/pgsql/data


Ubuntu tells me that it 'initdb' isn't installed. The instructions tell me this command is installed by 

sudo apt-get install postgresql


so what's going on?
If you haven't set up the environment variables, then you need to specify the full path to your executables.

What version of Postgresql are you using? You show a link to 8.3 which is many years old. These docs are current: http://www.postgresql.org/docs/current/static/creating-cluster.html

Did you install Postgresql with an up-to-date package, a la http://www.postgresql.org/download/linux/ubuntu/ ?

When installing 9.2 on Ubuntu, I added the following lines to the ~postgres/.bash_profile

export PATH=/usr/lib/postgresql/9.2/bin:$PATH:/usr/sbin
export PGDATA=/var/lib/postgresql/9.2/main
export PGPORT=5432


Where "/usr/lib/postgresql/9.2/bin" is the path to your 9.2 executables. That made the installation a bit smoother for me.