From owner-freebsd-stable@FreeBSD.ORG Fri Jan 8 21:49:48 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7EF481065676 for ; Fri, 8 Jan 2010 21:49:48 +0000 (UTC) (envelope-from noackjr@alumni.rice.edu) Received: from smtp106.biz.mail.re2.yahoo.com (smtp106.biz.mail.re2.yahoo.com [206.190.52.175]) by mx1.freebsd.org (Postfix) with SMTP id 1E7B68FC1A for ; Fri, 8 Jan 2010 21:49:48 +0000 (UTC) Received: (qmail 48127 invoked from network); 8 Jan 2010 21:23:05 -0000 Received: from 75-145-250-173-Connecticut.hfc.comcastbusiness.net (noackjr@75.145.250.173 with login) by smtp106.biz.mail.re2.yahoo.com with SMTP; 08 Jan 2010 13:23:05 -0800 PST X-Yahoo-SMTP: VnOecJeswBCMn50HlEMYJKFtvXTL X-YMail-OSG: 16ytPVYVM1lM.724oKFynWGUcq0z6GLQ4_T_gP.TLenqJpR7nEJs3rm2VwSNU7Z7Y8qGgaNVIv4tpSM77c__IMZ33EsPI_OLg_KpF3w66oOu4nq9zeb5_Ot_iyIKYpY_v67P4tWYm0gVs.LrE6dKTMerj7fOV_NCi_gRxY76cL1cDEriROZ.jwXohFU_EEafan1UhVQjQ5EFB4Absdyv9aOoE2MTe6id8fvK6uYa56ptcFe8NpwIOywvn5ktgDPL4ZSCd5vSAmVObJ.YEqQTnCe3nFFgOJP_KQ.GlhtfeiKIb5EFKG91YiWptmflpbSNSEM1EvepcKn9..gmMkTKUziajMVNHHgk1jcC4OyR8nrQtDVwqgjNR2kkFrRjL7gI2wV27Mrh92kNGV9AKH3QGZFvedxLllxKM6AOi7pMcmMpMnCdKbimeIL20eigVbucH0QSpW6sTexiJh2z3SGnNN4OeGch_TmSnKRs9pJHvvbnL4seYEO_ZIYpY46QWxxbFBhsI5u0lPeExyY7iKf4_qIFvyxlNURJoaST.6GB X-Yahoo-Newman-Property: ymail-3 Received: from optimator.noacks.org (localhost [127.0.0.1]) by optimator.noacks.org (Postfix) with ESMTP id 5039460FD; Fri, 8 Jan 2010 16:23:04 -0500 (EST) Received: from optimator.noacks.org ([127.0.0.1]) by optimator.noacks.org (optimator.noacks.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id l6Oft1pYB8tf; Fri, 8 Jan 2010 16:23:03 -0500 (EST) Received: from www.noacks.org (localhost [127.0.0.1]) by optimator.noacks.org (Postfix) with ESMTP id 3765B60D9; Fri, 8 Jan 2010 16:23:03 -0500 (EST) Received: from 192.168.1.1 (SquirrelMail authenticated user noackjr) by www.noacks.org with HTTP; Fri, 8 Jan 2010 16:23:03 -0500 Message-ID: In-Reply-To: <7346c5c61001080831w375d158fu5b1996ee58cb0f8d@mail.gmail.com> References: <7346c5c61001030842r7dc76199y51e4c1c90a3eea6e@mail.gmail.com> <7346c5c61001080831w375d158fu5b1996ee58cb0f8d@mail.gmail.com> Date: Fri, 8 Jan 2010 16:23:03 -0500 From: "Jonathan Noack" To: "Garrett Moore" User-Agent: SquirrelMail/1.4.20-RC2 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal Cc: freebsd-stable@freebsd.org Subject: Re: ZFS performance degradation over time X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: noackjr@alumni.rice.edu List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Jan 2010 21:49:48 -0000 On Fri, January 8, 2010 11:31, Garrett Moore wrote: > No, I haven't isolated the cause to only be uptime related. In my original > email I mentioned that "as suggested by someone in the thread, it's > probably > not directly related to system uptime, but instead related to usage - the > more usage, the worse the performance." > > I've been starting my system with different combinations of applications > running to see what access patterns cause the most slowdown. So far, I > don't > have enough data to give anything concrete. > > This weekend I'll try some tests such as the one you describe, and see > what > happens. I have a strong suspicion that rTorrent is to blame, since I > haven't seen major slowdowns in the last few days with rTorrent not > running. > rTorrent preallocates the space needed for the file download (and I'm > downloading large 4GB+ files using it), and then writes to them in an > unpredictable pattern, so maybe ZFS doesn't like being touched this way? Probably unrelated, but this prefetch issue results in a slowdown: http://lists.freebsd.org/pipermail/freebsd-fs/2009-December/007481.html -Jonathan