Fixing blank pages on mediawiki

I installed media wiki today for a project of mine and noticed that it generated blank pages when trying to click on anything other than the main page. This was pretty annoying and google provided little for results on what normally fixes this. I dug into this using the methods below and eventually brought it to resolution:

Step 1. I knew that php was puking for some reason so I needed a verbose way of knowing why, by default php logging is not enabled in ubuntu server so I needed to edit the following directive in the /etc/php5/apache2/php.ini to get more info:

; Log errors into a log file (server-specific log, stderr, or error_log (below))
; As stated above, you're strongly advised to use error logging in place of
; error displaying on production web sites.
log_errors = On

Step 2. Now that logging was enabled I could get a better assessment of the error by tailing the apache log file:

# tail /var/log/apache2/error.log | grep php
[Sat Apr 17 05:35:01 2010] [error] [client 192.168.1.3] PHP Fatal error:  Allowed memory size of 20971520 bytes exhausted (tried to allocate 14 bytes) in /var/www/wiki/includes/SpecialPage.php on line 234, referer: http://internal/wiki/index.php/Main_Page

Step 3. Now that I knew it was a php memory allocation issue I modified the php.ini to have more memory ( default was 16MB ):

memory_limit = 128M      ; Maximum amount of memory a script may consume (16MB)

Step 4. But the error still existed… After doing some digging the ultimate resolution was to edit the memory_limit configuration directive to mediawiki itself in LocalSettings.php which was set to 20MB by default:

# If PHP's memory limit is very low, some operations may fail.
ini_set( 'memory_limit', '32M' );

Once this was done the wiki started responding normally