From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161032AbWGZUSx (ORCPT ); Wed, 26 Jul 2006 16:18:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161031AbWGZUSx (ORCPT ); Wed, 26 Jul 2006 16:18:53 -0400 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:8128 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S1161032AbWGZUSw (ORCPT ); Wed, 26 Jul 2006 16:18:52 -0400 Subject: Re: 3ware disk latency? From: Alan Cox To: dean gaudet Cc: Jan Kasprzak , linux-kernel@vger.kernel.org In-Reply-To: References: <20060710141315.GA5753@fi.muni.cz> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 26 Jul 2006 21:37:29 +0100 Message-Id: <1153946249.13509.29.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 (2.6.2-1.fc5.5) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ar Mer, 2006-07-26 am 09:52 -0700, ysgrifennodd dean gaudet: > On Mon, 10 Jul 2006, Jan Kasprzak wrote: > > > Does anybody experience the similar latency problems with > > 3ware 95xx controllers? Thanks, > > i think the 95xx is really bad at sharing its cache fairly amongst > multiple devices... i have a 9550sx-8lp with 3 exported units: a raid1, a > raid10 and a jbod. i was zeroing the jbod with dd and it absolutely > destroyed the latency of the other two units. Even on the older 3ware I found it neccessary to bump up the queue sizes for the 3ware. There's a thread from about 6 months ago (maybe a bit more) with Jeff Merkey included where it made a huge difference to his performance playing with the parameters. Might be worth a scan through the archive. Alan