As far as I know, if you want to install BuddyPress you’ve got to have a WordPress MU installation (I know WordPress 3.x already is MU in itself) with a unique database, which has different tables for each blog.
But my situation is quite different: we have a blog network, and we would like to have a buddypress installed for all our blogs. This way users could register once and comment on the blogs automatically, see their activity, link to other users, etc. But the blogs are on different servers 🙁
Our current physical division of blogs (some of them are together in the same server, but others are in different servers, each with its own database) makes me think this is quite difficult to do. I know that the Multi-DB plugin could help us with the database thing, but… what if the blogs are, as in our situation, in different servers/VPS’s?
“As far as I know, if you want to install BuddyPress you’ve got to have a WordPress MU installation “
No, you do not. You can install BuddyPress on a single WordPRess installation.
If the blogs are all on different server,s then you do not have what is meant by a WordPress network (multisite – what WAS MU) and the multi DB plugin will not help you.
I can’t see any way to do what you want without synching the user tables across everything.
You could Setup a Multisite Network (formerly MU) and migrate existing wordpress sites to this network either manually or using a tool like backupbuddy which has a great multisite import tool. Then setup buddypress and then repoint dns to use the new sites. Just a thought. Oh and i highly recommend the multi-db plugin and running either a vps or cloud server with nginx if you intend on running multiple buddypress sites. Will make your sites lightning fast and fairly future proof.
The lead developer of Buddypress said you can only install buddypress on one wordpress installation. Also what andrea_r said.
BuddyPress on Multisite