Finally , I successfully upgrade from 6.5.4 to 7.0.2 (Except some Chinese character encoding problems... I'll inspect these problems later)
It takes me a whole day to transfer about 800000 posts and 55000 users ...
My old 6.5.4 is in /ubbthreads directory , with old data (files / avatars / styles ...)
The UBBT 7.0.2 is installed in /ubbthreads7 directory
I don't want my site contains new ubbthreads7 and old ubbthreads directory. I want to combine the two directories.
I noticed UBB7 seems very clean , only have two php files in the root directory (index.php , ubbthreads.php) , can I use 'cp -r ubbthreads7 ubbthreads' to overwrite the whole old UBB6 (and remove all unnecessary php files) ? Of course , I'll modify all path-related parameters (from ubbthreads7 -> ubbthreads) , and then replace UBB6's , postlist.php , showflat.php , showthreaded.php with importer's ...
Will this work ? Anything missing ?