In 10g, with filesystemio_options=setall, oracle will issue the O_CIO flag with it's calls to open the files, so it doesn't have to be set as the default for the filesystem. The CIO option only specifies the default method of opening the files for that filesystem, but you can open a file with CIO on a non-CIO filesystem and vice-versa. Regards, Brandon -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of cnewtonne@xxxxxxxxx Just for curiosity, why does not 10g require it? 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