How to migrate Wordpress Blogs into Multisite without using the GUI-Import/Export Feature

Question

I'd like to migrate some quite huge Wordpress-Blogs into one Multisite Installation.

The Export-Wizard and the Import Wizard are bound to PHP-Limits (Memory, Execution-Time) and so the Export and Import often fails.

There must be a way to do it by hand (only using MySQL and or the command line).

Answer 1

http://bavatuesdays.com/importing-a-single-wp-blog-to-a-wpmu-installation/

http://sillybean.net/wordpress/migrating-single-wordpress-installations-into-multisite-networks/

Answer 2

I also wrote this lately: http://wp.leau.co/2010/12/24/moving-a-weblog-to-a-wp3-multisite-weblog-system-on-mediatemple/ with a note for specific mediatemple take-care-things.