From owner-freebsd-stable@FreeBSD.ORG Sat May 2 21:37:50 2009 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 53BD41065670 for ; Sat, 2 May 2009 21:37:50 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from yw-out-2324.google.com (yw-out-2324.google.com [74.125.46.30]) by mx1.freebsd.org (Postfix) with ESMTP id 081478FC12 for ; Sat, 2 May 2009 21:37:49 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: by yw-out-2324.google.com with SMTP id 9so1886042ywe.13 for ; Sat, 02 May 2009 14:37:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=OcfR87HXvWPDBA0TtmY4Ylwzd4g1qegNzhFJFgr6SeM=; b=H04T66UYZJmlj0dkQnd9Jeu7ESgTHok60Se3Vm3PBFPxvpoVy9pQA788EcCcTBMsx5 V/alQKVJ8fDotFt901DwBuWfu1Dji6qT+IzVtWVpbYc8Jw/ypugjpQgHIuuL+k27ZupC cNibLNCwgFWI5wEMV0mLBskhw1vBgnQZ2xoXw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=A6bRsfhgCf1diCCJiJlnxiYXkyuI/f/kisiBuDj35pc9n2lSa9hrLaSXi52QwOBnLy Lg06jMKtIjhjjsb/dw2Tcw0kQ27HBvTJv3DnbsTrc52eUTJIWmvkKykqI65NvsMPDXUg E5DYWaZR07oFXv9AqO2i29bTAHcVJKVBv295E= MIME-Version: 1.0 Received: by 10.151.135.8 with SMTP id m8mr8521124ybn.228.1241300269433; Sat, 02 May 2009 14:37:49 -0700 (PDT) In-Reply-To: References: <32A0BDD9-ACF8-43F4-8D2C-0FC151F1D7CB@cryptomonkeys.org> Date: Sat, 2 May 2009 14:37:49 -0700 Message-ID: From: Freddie Cash To: FreeBSD Stable Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: current zfs tuning in RELENG_7 (AMD64) suggestions ? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 May 2009 21:37:50 -0000 On Sat, May 2, 2009 at 12:11 PM, Alan Cox wrote: > On Fri, May 1, 2009 at 6:28 PM, Freddie Cash wrote: >> On Fri, May 1, 2009 at 4:12 PM, Louis Kowolowski >> wrote: >> > On May 1, 2009, at 1:53 PM, Pete French wrote: >> >> ... >> >> The tuning isn't there to improve performance, it's there to prevent >> >> the box going titus due to a panic when the ARC gets too big, and >> >> you are missing the mian one, which is to limit the size of the ARC. >> >> On recent versions of BSD (and you are running 7.2, so thats fine) th= en >> >> the defaults for kmem size are fine, but you still need something lik= e >> >> this: >> >> >> >> vfs.zfs.arc_max=3D"256M" >> >> >> >> In there to stop the ARC growing. thats the only tuning I have on >> >> my 4 gig machine, which takes a steady stream of data and is used >> >> for taking backup snapshots. ZFS is excellent, and for me is perfectl= y >> >> stable, to the point where I am starting to roll it out to production >> >> machines, with the above tuning. >> >> >> > I agree, although I'm using 384 instead of 256. =C2=A0My systems have = been >> > running in production for almost a year now w/o any ZFS issues. >> >> The exact value to use will depend on the system. =C2=A0Particularly on = the >> amount of RAM in the system, and what kmem_max is set to. =C2=A0A >> "rule-of-thumb" we've been using is: >> =C2=A0 kmem_max should be half of the amount of RAM (or 1.5 GB as that's >> the current max) > > This information is outdated.=C2=A0 The current max in RELENG_7 for amd64= is > ~3.75GB. Nice! Good to hear. Thanks for the correction. Looking forward to testing this with 7.2. --=20 Freddie Cash fjwcash@gmail.com