From owner-freebsd-fs@FreeBSD.ORG Fri Dec 25 11:23:54 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F16F31065670 for ; Fri, 25 Dec 2009 11:23:54 +0000 (UTC) (envelope-from solon@pyro.de) Received: from srv23.fsb.echelon.bnd.org (mail.pyro.de [83.137.99.96]) by mx1.freebsd.org (Postfix) with ESMTP id A1E868FC12 for ; Fri, 25 Dec 2009 11:23:54 +0000 (UTC) Received: from port-87-193-183-44.static.qsc.de ([87.193.183.44] helo=MORDOR) by srv23.fsb.echelon.bnd.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1NO8Gs-0006lv-G6; Fri, 25 Dec 2009 12:23:53 +0100 Date: Fri, 25 Dec 2009 12:23:31 +0100 From: Solon Lutz X-Mailer: The Bat! (v3.99.25) Professional Organization: pyro.labs berlin X-Priority: 3 (Normal) Message-ID: <982740779.20091225122331@pyro.de> To: Thomas Burgess In-Reply-To: References: <568624531.20091215163420@pyro.de> <42952D86-6B4D-49A3-8E4F-7A1A53A954C2@spry.com> <957649379.20091216005253@pyro.de> <26F8D203-A923-47D3-9935-BE4BC6DA09B7@corp.spry.com> <1696529130.20091223212612@pyro.de> <1266543768.20091225120330@pyro.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Spam-Score: -1.4 (-) X-Spam-Report: Spam detection software, running on the system "srv23.fsb.echelon.bnd.org", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see The administrator of that system for details. Content preview: > Depending on tuning, you can make it flush to disk more often. It is also highly dependent on how much memory you have. At the moment: 4GB. I'm about to try upgrading it to 6GB. Why can't it work like this all the time: [...] Content analysis details: (-1.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.4 ALL_TRUSTED Passed through trusted hosts only via SMTP X-Spam-Flag: NO Cc: freebsd-fs@freebsd.org Subject: Re: ZFS RaidZ2 with 24 drives? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Dec 2009 11:23:55 -0000 > Depending on tuning, you can make it flush to disk more often. It is also highly dependent on how much memory you have. At the moment: 4GB. I'm about to try upgrading it to 6GB. Why can't it work like this all the time: device r/s w/s kr/s kw/s wait svc_t %b da0 0.0 1907.4 0.0 65494.8 0 0.6 6 ad10 680.7 0.0 87132.0 0.0 35 43.7 92 Effectively, it transfers 8-10MB/s! Took 24h for 1.2TB... > I know on my personal system, i see this happen a lot but it doesn't seem to have a hugely negative impact on > performance for what i use my machine for. Depending on your setup, you may want to try various sysctl settings. I > found that disabling prefetch can have a huge impact on some systems. Prefect is not enabled because of RAM < 4GB... Can you name an tuneable sysctls? Best regards, Solon