MOS note 1621469.1 captured my attention, as we have just implemented OBIEE again but on the 11g platform this time but I haven't had a lot of exposure to that or DBFS. What is DBFS? The note has a good explanation, I'll need to find more documentation about the subject later, but it boils down to a File System for Oracle Databases that can be used instead of NFS or ZFS based on SecureFile LOBs with access controlled with PL/SQL procedure calls.
The point of the article was if DBFS can be used for OBIEE 11g, and I'll steal a bit of thunder for once and tell you no it can't be used. What I won't tell you, is WHY that is the case, and if you are curious you can visit the MOS note!