I just finished migrating a high profile site with about 150 MB of textual content from a WordPress 2.2 install over to WordPressMU 2.7. Here are some tips to make your experience a little easier than mine was.
Moving content from one WordPress site to another is fairly straightforward, as long as:
- You’re not moving from WordPress to WordPressMU. WordPressMU has a table structure that differs from that of plain vanilla WordPress, so some extra steps are needed (more on this below).
- You have less than about 2 MB of content on your WP site. There are some hard file limits on the built-in import and export functions of WordPress that severely limit its usefulness. In fact it’s almost impossible to migrate a large site using these features.
- You’re going from WordPress 2.5+ to WordPress 2.5+. The database scheme is different prior to WordPress 2.5, as this was the version that introduced user-defined taxonomies for categories and tags. So simply moving source tables to destination table won’t work.
In my case, I was going from WP 2.2 to WPMU 2.7, with the old 2.2 site becoming one of the “member sites” on the new 2.7 installation. Here are the steps I followed: