Trying to update my CE from 15x to the latest

http://www.observium.org/docs/updating/

Ran:

cd /opt

mv observium observium_old

wget -Oobservium-community-latest.tar.gz http://www.observium.org/observium-community-latest.tar.gz

tar zxvf observium-community-latest.tar.gz

mv /opt/observium_old/rrd observium/

mv /opt/observium_old/*log* observium/

mv /opt/observium_old/config.php observium/

[root@rtg opt]# /opt/observium/discovery.php -u

PHP Fatal error:  require(): Failed opening required '/opt/observium/config.php' (include_path='.:/usr/share/pear:/usr/share/php') in /opt/observium/includes/sql-config.inc.php on line 26