From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Denk Subject: Re: Optimize RAID0 for max IOPS? Date: Tue, 25 Jan 2011 13:45:09 +0100 Message-ID: <20110125124509.D76D6BB0B9@gemini.denx.de> References: <20110118210112.D13A236C@gemini.denx.de> <4D361F26.3060507@stud.tu-ilmenau.de> <20110119192104.1FA92D30267@gemini.denx.de> <20110124215713.82D75B187@gemini.denx.de> <20110124230314.GA11040@dastard> <20110125083900.4dd65bf2@galadriel2.home> <20110125083643.GE28803@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: In-reply-to: <20110125083643.GE28803@dastard> Sender: linux-raid-owner@vger.kernel.org To: Dave Chinner Cc: Emmanuel Florac , linux-raid@vger.kernel.org, Justin Piszcz , xfs@oss.sgi.com List-Id: linux-raid.ids Dear Dave Chinner, In message <20110125083643.GE28803@dastard> you wrote: > > Oh, despite $subject being "RAID0" the filesystems being tested are > on RAID5 and RAID6 with very small chunk sizes on slow SATA drives. > This is smelling like a case of barrier IOs on software raid on > cheap storage.... Right. [Any way to avoid these, btw?] I got side-tracked by the comments about the new (to me) delaylog mount option to xfs; as the results were not exactly as exp[ected I though it might be interesting to report these. But as the subject says, my current topic is tuning RAID0 to avoid exactly this type of bottleneck; or rather looking for tunable options on RAID0 Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de PLEASE NOTE: Some Quantum Physics Theories Suggest That When the Con- sumer Is Not Directly Observing This Product, It May Cease to Exist or Will Exist Only in a Vague and Undetermined State.