Allen, I too use AIX CIO and have been for years, for performance enhancement reasons. I've used these archives to rebuild my dev environment so I too know these are good. Patrick. --- On Tue, 5/25/10, Allen, Brandon <Brandon.Allen@xxxxxxxxxxx> wrote: From: Allen, Brandon <Brandon.Allen@xxxxxxxxxxx> Subject: AIX Concurrent I/O for Oracle archive logs To: "oracle-l@xxxxxxxxxxxxx" <Oracle-L@xxxxxxxxxxxxx> Date: Tuesday, May 25, 2010, 9:06 AM Hi List, Can anyone think of a good reason why Oracle’s archived redo logs shouldn’t be placed on a non-buffered (concurrent or direct IO) file system? Oracle Support document 418714.1 specifically states NOT to use DIO/CIO for file systems containing archive logs. However, I have one AIX system where my archive logs have been on a file system mounted with CIO for years and I’ve never had any problems (and yes, I’ve successfully used the logs for actual recovery). I’m considering moving another of my systems to CIO because on the other system, when archive log backups run, the AIX file system cache gets flooded by the archive logs and it has recently started causing the OS to start paging heavily, which in turn is bringing the system to a screeching halt for a few minutes, so I think if I move the logs to a CIO file system then they should no longer be read into the AIX buffer cache, and that should prevent this problem, but I just want to see if anyone has any good reasons why I should avoid using CIO with archive logs. Thanks, 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.