I'm guessing they did it to enable concurrent IO to the online redo logs, which should give better I/O performance for those files as described here: http://download.oracle.com/docs/cd/E11882_01/server.112/e10839/appa_aix.htm#sthref492 And on here (p.26): http://public.dhe.ibm.com/partnerworld/pub/whitepaper/162b6.pdf Regards, Brandon Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it. -- //www.freelists.org/webpage/oracle-l