Re: DBWR, Direct I/O and the Devil

From: Don Seiler <don_at_seiler.us>
Date: Wed, 28 Nov 2007 15:22:23 -0600
Message-ID: <716f7a630711281322k3c94d109ge3120f61ee8297cf@mail.gmail.com>

On Nov 28, 2007 3:07 PM, Bobak, Mark <Mark.Bobak_at_il.proquest.com> wrote:
> I think you want both direct *and* async I/O configured, if your O/S and filesystem will support it. In that case (with async i/o) you probably will only need 1 DBWR.

Alright so I should set filesystemio_options=setall rather than directio? Are there any other parameters to look at?

Don't I still need to mount the disk with "mincache=direct,convosync=direct"?

> http://www.ixora.com.au/tips/avoid_buffered_io.htm
> http://www.ixora.com.au/tips/use_asynchronous_io.htm

Yep I've been reading this already.

My connotation was that direct I/O the opposite of asynchronous I/O. I'm seeing now that they are more or less independent states of I/O covering different aspects of behavior.

-- 
Don Seiler
http://seilerwerks.wordpress.com
ultimate: http://www.mufc.us
--
http://www.freelists.org/webpage/oracle-l

Received on Wed Nov 28 2007 - 15:22:23 CST