title: How to thoroughly purge and reinstall postgresql on ubuntu?
body: <p>Somehow I've managed to completely bugger the install of postgresql on Ubuntu karmic.  I want to start over from scratch, but when I "purge" the package with apt-get it still leaves traces behind such that the reinstall configuration doesn't run properly.</p>
  
  <p>After I've done:</p>
  
  <pre><code>apt-get purge postgresql
  apt-get install postgresql
  </code></pre>
  
  <p>It said</p>
  
  <pre><code>Setting up postgresql-8.4 (8.4.3-0ubuntu9.10.1) ...
  Configuring already existing cluster (configuration: /etc/postgresql/8.4/main, data: /var/lib/postgresql/8.4/main, owner: 108:112)
  Error: move_conffile: required configuration file     /var/lib/postgresql/8.4/main/postgresql.conf does not exist
  Error: could not create default cluster. Please create it manually with
  
    pg_createcluster 8.4 main --start
  
  or a similar command (see 'man pg_createcluster').
  update-alternatives: using /usr/share/postgresql/8.4/man/man1/postmaster.1.gz to provide /usr/share/man/man1/postmaster.1.gz (postmaster.1.gz) in auto mode.
  
  Setting up postgresql (8.4.3-0ubuntu9.10.1) ...
  </code></pre>
  
  <p>I have a "/etc/postgresql" with nothing in it and "/etc/postgresql-common/" has a 'pg_upgradecluser.d' directory and root.crt and user_clusters files.</p>
  
  <p>The /etc/passwd has a postgres user; the purge script doesn't appear to touch it.  There's been a bunch of symptoms which I work through only to expose the next. </p>
  
  <p>Right this second, when I run that command "pg_createcluster..." it complains that '/var/lib/postgresql/8.4/main/postgresql.conf does not exist', so I'll go find one of those but I'm sure that won't be the end of it.</p>
  
  <p>Is there not some easy one-liner (or two) which will burn it completely and let me start over?</p>