I've had a site for a few years that till yesterday consisted of two WP 3.2.1 installations- one for the main site and one for the blog, which had a different theme and was located at [site.com]/blog.
We need a few more blogs now, and I wanted to unify the user database, so I decided to convert the main site into a network and then migrate the blog over as a new site within the network.
Initial issues were:
- WP doesn't allow existing sites to use the subfolder system when converting to a multisite network (only subdomain)
- Got around this by first going with subdomain, then switching to subfolder with appropriate changes in wp-config.php and .htaccess, as documented here
- WP doesn't allow you to create a network site called "blog"
- I got around this by creating a site with some really random name, then just searching through the DB and replacing that name with "blog", resulting in a site called "blog" (WP only enforces the "blog" name ban upon site creation)
- The main site gets a hardcoded "blog" slug for all permalinks
- I used this workaround to remove the slug (basically go to network admin panel, edit settings for main site, manually remove "blog" from the permalink, then go to main site dashboard, open permalink settings (but don't edit or save))
So now I have a site (in the network admin settings) called "blog," the posts on the main site are now back to the old permalinks (e.g. [site.com]/2012/01/20/hello-world), and even categories and such are working fine on the main site.
Problem is I'm unable to actually access the new "blog" subsite. Going to [site.com]/blog/wp-admin shows me the main site's dashboard, instead of the new "blog" subsite's. More strangely, going to [site.com]/blog redirects to [site.com]/2011/05/04/blog/ and gives a 404 (no idea where that date, etc. are coming from).
Main reason I need the subsite to be [site.com]/blog is I want to avoid breaking all the links we have out on FB/Twitter/etc.