Notes/Domino 4 and 5 Forum

Hi, I'm in this situation:

I have 2 database (size = 6.37GB and 3.18GB), 450GB of free space in disk and I'm getting the follwing error when I try to update their Full Text Index:

"Error full text indexing document XXX in database <database_index_path>. Full text Error - not enough space in disk to build index.
Error full text indexing <database_path>Full text Error - not enough space in disk to build index."

I've allready done a fixup and tried to re build them but the same happens , and I really don't think there's a problem with disk space.
Is there any way to configure where to run the index generation or any other alternative?

thanks.