we have several DELL 6800 with LSI 4e/DC adapter cards (128 MB cache) in it. DELL 6800 run under Redhar AS 4.0 and ORACLE 9ir2. When I configured DELL 6800 server local disks (Mirror or RAID 5), ther have two I/O policy to choice - direct IO and cache IO. I doing simple test by copy files between differents disk set and found "direct IO" performance better than "cache IO". It is against what I read before. I used to saw documents from SUN and IBM said "large disk array cache will improve I/O performance". Any one has suggestion FOR ORACLE server which I/O policy should I setup? Thanks. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- //www.freelists.org/webpage/oracle-l