WordPress MU

How do I change the permalink structure globally for all blogs created? In WP you can do that in the options page but where in MU? I'd like this type of structure:
/%category%/%postname%/

Thanks

bump>>

I dont know that you can. But if you can my guess would be that you would do it with a combination of htaccess and the options panel.

In WP I know it rewrites htaccess. I thought about just copying that from a regular WP installation and putting it into my WPMU htaccess. I'm pretty sure that would just screw things up though. I was hoping that there'd be an easier way.

I hope this is someting that they bring from WP and put into WPMU.

bump>>

i hope someone can help..

If you go to Site Admin, edit a blog you'll find permalink structure in the list.

However, I just changed mine and broke the site :(

Anyone have any idea why a permalink structure of :

/%year%/%monthnum%/%day%/%postname%/

works (this is the default)

but

/%category%/%postname%/

doesn't?

Just gives me a 404 each time.

I don't know why /%category%/ doesn't work, http://codex.wordpress.org/Using_Permalinks sais it has problems with some versions of apache.

The default permalink structure is set up when running the wordpress mu install.

index-istall.php:
//line 399
update_blog_option( 1, 'permalink_structure', '/blog/%year%/%monthnum%/%day%/%postname%/');

Does anyone know how can I change this after the WPMU install?

No. All permalink structure and mutch more for new blogs in upgrade-schema.php

add_option('permalink_structure', '/%year%/%monthnum%/%day%/%postname%/');