From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rabbitson Subject: Re: raid10 far layout outperforms offset at writing? (was: Help with chunksize on raid10 -p o3 array) Date: Wed, 17 Dec 2008 13:50:24 +0100 Message-ID: <4948F590.2050007@rabbit.us> References: <20081217124154.GA5406@rap.rap.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20081217124154.GA5406@rap.rap.dk> Sender: linux-raid-owner@vger.kernel.org To: =?UTF-8?B?S2VsZCBKw7hybiBTaW1vbnNlbg==?= Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Keld J=C3=B8rn Simonsen wrote: > I found this old message: >=20 >> Peter Rabbitson >> Mon, 19 Mar 2007 06:14:38 -0800 >> >=20 > The links were not valid anymore. I wanted to see the results and=20 > possibly include the results in the performance wiki page > I would appreciate some new links here. I apologize, I don't have the data available anymore. > Furthermore some comments to the post: My take on o3 vs f3 is that bo= th > in theory and practice f3 should be much faster for sequential readin= g, > as the layout is equivalent to raid0. For random reading and sequenti= al > and random writing f3 and o3 (and the same goes for the more normal f= 2 > vs o2) should be about the same, especially when a filesystem and > its associated elevator algorithm is employed. Yes, this is what I also concluded since I wrote this email. I am in th= e process of upgrading my raid setup, and while I am at it I am leaving 5GB blank partitions at the start of all my workstations spindles, so I can get some real testing at night. I will share my methodology with th= e list before I commence testing (which should take about 20 days the way I am planing it). But first comes the vacation - happy holidays to you too guys. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html