WordPress MU

i'm a proud user of Donncha's Site Wide Tags plugin. Now i'm modifying my website, and i want to use the main blog as global blog (i'have used the "tags blog" since now, but i need to change this).

Checking the main blog as global blog, i'm afraid that all the old posts will not populate the main blog. What is the easiest way to start from zero, deleting the tags blog and populating my main blog with all the old posts (without loosing right links to the individual blog posts)?

Thanx!

ps: i'm not running hundred of blogs, only one individual sub blog with 400 posts.

"Checking the main blog as global blog, I'm afraid that all the old posts will not populate the main blog. "

Did you try it? If you do, and it doesn't work, it will just leave the old posts where they are.

"What is the easiest way to start from zero, deleting the tags blog and populating my main blog with all the old posts (without loosing right links to the individual blog posts)?"

Export / Import ?

thanx Andrea for your reply. Yes, i've done my try before posting here, but you know: site wide tags (that i love) is very "delicate", and when it stop working is a real pain.

However i wanna post some tricks:

if you have an existing blog, and then you want to republish all the posts in the main blog using donncha site wide tags plugin, check the "post to main blog option". The posts will be published but in the wrong categories.

So i've:
1 exported my sub blog
2 Deleted the sub blog
3 create a new blog with the same name
4 imported all posts

now the main blog won't pick tags and categories until you've click "publish" to EVERY single post of your blog, and so it is a bit hard...cause i have more than 400 posts.

But after this, the double publishing works, for new posts too.