The permalinks now all have the structure /%year%/%monthnum%/%postname%/ where the previous the structure was /%post_id%. Permalink rewrites are based on the Apache Rewrite engine and there are a few caveats when changing the permalink structure. Here’s a checklist to get you going…

First of all, you must make sure that the mod_rewrite module is loaded in your apache instance.

root@export:/var/www/blog# apache2ctl -t -D DUMP_MODULES

and check for

rewrite_module (shared)

If not, checkout the apache document on rewrite engine to enable this module in your apache instance.

Finally, make sure your virtual host configuration has :

RewriteEngine On

When changing the permalink structure in your Wordpress backend, it will generate a .htaccess file. This is what it looks like for our permalink structure :

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Normally, this is supposed to be the end of the story but when you receive a 404 surfing to your newly generated links, then verify the following two settings in your virtual host configuration :

• The FollowSymLinks option enabled
• FileInfo directives allowed (e.g. AllowOverride FileInfo or AllowOverride All)

Good luck!

PS: If you don’t want to loose your pagerank for the posts that have incoming links using the old permalink structure, go checkout  “Dean’s Permalinks Migration 1.0“. This will redirect the old permalinks to your new structure, and keep Google happy It is available from the plugins menu in the Wordpress backend.