We have seen significant improvements when we enable CIO option of the JFS2 filesystem where redo logs resides.If you are on JFS2 filesystem, I would recommend you to have a try with CIO option enable on this filesystem (where redo logs resides). Regards, Jaffar On Tue, Sep 9, 2008 at 7:32 AM, Deepak Sharma <sharmakdeep_oracle@xxxxxxxxx>wrote: > We recently (today) moved the redo logs from RAID5 to RAID1+0. > > The obvious reason of doing this is to make things better in terms of > performance, as RAID1+0 is better suited for read/writes. Someone pls > correct me if that's not true. > > What are different ways to measure the impact of this change? > > The platform is AIX, DB is 10.2.0.3 and DB size is 55TB, and 2TB redo is > generated each day. There are plans underway to reduce the redo generation > using direct path etc. (so let's not get diverted by that). > > We can try measuring the wait event stats using AWR, session stats etc., > but what exactly to look for? 'log file switch completion', 'log file > sync', are some things that come to mind - what else? > > Thanks, > Deepak > > > -- Best Regards, Syed Jaffar Hussain Oracle ACE 8i,9i & 10g OCP DBA RAC Certified Expert Official Oracle RAC SIG Representative for Saudi Arabian region ( http://www.oracleracsig.org/) http://jaffardba.blogspot.com/ http://apex.oracle.com/pls/otn/f?p=19297:4:1579866181463918::NO:4:P4_ID:126 ---------------------------------------------------------------------------------- "Winners don't do different things. They do things differently."