From owner-freebsd-stable@FreeBSD.ORG Thu Jun 18 15:25:51 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 E4903106566C for ; Thu, 18 Jun 2009 15:25:50 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-gx0-f207.google.com (mail-gx0-f207.google.com [209.85.217.207]) by mx1.freebsd.org (Postfix) with ESMTP id 892228FC14 for ; Thu, 18 Jun 2009 15:25:50 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: by gxk3 with SMTP id 3so1575999gxk.19 for ; Thu, 18 Jun 2009 08:25:50 -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; bh=4y+564LWvS1iAcbM110Gyh7+VKeLUc6/sQbUsdhKucw=; b=a/mZJ84rOeEBd8TGaB4fhQEiUtGPS4oi/lSm+16tX7rk1o5li/BYXh77uTG4Rh13PN oyDgEQEGaRJGKJE6sIlGDBCjM5QMUXJ6XMm7xoCLhvCrNttYKnIwhWXuFZ3lJSDcvU8v p6wuNWbXEqlgnzJMMSs1CHqNqFKA2JeThJdzg= 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; b=NPNXj2SyMEkz9Y0u1JQkQhYei8f/AH9DGPlTzLPAQ0OMDf21F3TyGs5YUgRJrUigcG bb9avwW0khYqCl+bKC45R9mBAmoSYALkgYeJN+BGKXFBp8KdwEx4Jk1M0b5xtK6xCdJn ybZEcotcoIDK0PKubCzMrxus0USrehOlHPruU= MIME-Version: 1.0 Received: by 10.150.124.11 with SMTP id w11mr3757247ybc.276.1245338749519; Thu, 18 Jun 2009 08:25:49 -0700 (PDT) In-Reply-To: References: Date: Thu, 18 Jun 2009 08:25:47 -0700 Message-ID: From: Freddie Cash To: freebsd-fs@freebsd.org, FreeBSD Stable Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Subject: Re: ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates 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: Thu, 18 Jun 2009 15:25:51 -0000 On Thu, Jun 18, 2009 at 1:29 AM, Pete French wrote: > > All the ZFS tuning guides for FreeBSD (including one on the FreeBSD > > ZFS wiki) have recommended values between 64M and 128M to improve > > stability, so that what I went with. How much of my max kmem is it > > safe to give to ZFS? > > If you are on amd64 then don't tune it, it will tune itself. If you > are on i386 (or an earlier verions of amd64) then 128M on a 2 gig machine > should be OK, assuming you have kmem_size_max set to the full 1500 odd. > Those are numbers which come up time and time again - I ran reliably with > them for ages, until the latest -STABLE. > My "rule of thumb" for 32-bit i386 systems has been to: - assign half of RAM to kmem (up to the max of ~1500 on 7.0/7.1) - assign half of kmem to zfs_arc_max So far, for my workloads (nfs/cifs file servers, cups print servers, rsync servers, kde4 desktop), it's worked well. -- Freddie Cash fjwcash@gmail.com