Thanks to all for assisting me in arriving at the storage design for our database. Kevin, We have on board RAID controller for the internal SAS disks. Sorry for not mentioning earlier. As you are suggesting to go with HW RAID, would like to understand whether redundancy provided by RAID using failure groups is less efficient than HW RAID? Should we always use external redundancy instead of ASM redundancy (if it is available)? --Deepak On Tue, Apr 26, 2011 at 10:15 PM, Niall Litchfield < niall.litchfield@xxxxxxxxx> wrote: > Vishal, > I'm struggling to work out how this behaviour affects the design choice in > storage layout. > > On 26 Apr 2011 17:17, "Vishal Gupta" <vishal@xxxxxxxxxxxxxxx> wrote: > > On RHEL5, CFQ i/o scheduler is broken. Under heavy load performance > improves with deadline i/o scheduler. On RHEL4 it does not give much > benefit. There is linux bug for broken CFQ on RHEL5. > > > http://www.google.co.uk/url?sa=t&source=web&cd=1&sqi=2&ved=0CBYQFjAA&url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D456181&ei=tDaKTcvzNeWG0QHYybzoDQ&usg=AFQjCNEKaFfKVmLhVeoMgJzoaGyeRXS15w > > http://www.google.co.uk/url?sa=t&source=web&cd=2&sqi=2&ved=0CBwQFjAB&url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D427709&ei=tDaKTcvzNeWG0QHYybzoDQ&usg=AFQjCNEZHzLC3u7lkB3nE-1ZNbI7hvboFQ > > http://www.google.co.uk/url?sa=t&source=web&cd=3&sqi=2&ved=0CCIQFjAC&url=https%3A%2F%2Fbugzilla.redhat.com%2Fshow_bug.cgi%3Fid%3D448130&rct=j&q=redhat%20cfq%20bug%20i%2Fo%20slow&ei=tDaKTcvzNeWG0QHYybzoDQ&usg=AFQjCNGdlO8BfKyUeWrifJLtybLszRGsBg > > > Regards, > Vishal Gupta > http://www.vishalgupta.com > > ------------------------------ > *From:* oracle-l-bounce@xxxxxxxxxxxxx on behalf of Kevin Closson > *Sent:* Tue 26/04/2011 16:45 > *To:* Oracle-L > > > Subject: Re: ASM+internal disks > > Here's how I look at this. The following are true 1) there is no networked > storage so all disks are ... > > -- Regards, Deepak Oracle DBA