From owner-freebsd-stable@FreeBSD.ORG Thu May 9 13:52:39 2013 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id EFCFD8AE for ; Thu, 9 May 2013 13:52:39 +0000 (UTC) (envelope-from tevans.uk@googlemail.com) Received: from mail-la0-x232.google.com (mail-la0-x232.google.com [IPv6:2a00:1450:4010:c03::232]) by mx1.freebsd.org (Postfix) with ESMTP id 7E02D916 for ; Thu, 9 May 2013 13:52:39 +0000 (UTC) Received: by mail-la0-f50.google.com with SMTP id fl20so2871286lab.9 for ; Thu, 09 May 2013 06:52:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=7GDitFT8aT7KJ6kzKHeAFfxA59bmiz09qAeWmyXKokk=; b=J93cKsYrzEjeHEsW78CDjAcl+dQh3jT/+DhfstnIXPGR4BR9Eb/ka27mjUuMn+Hz0w siuguO2Ovs8tG8T5mKa0xycjeDEFarLgeEfX0NNXAKMBDqvaVM16JvX5tk902L1+nUaI u+KefF8UsRP9pzyqEyrraniwyqH8voMZcvNXYIJUkuD8YS0vsgBEvz5CkcMwqfa8nlcq gMviyHTO82pK/atAIpqtZgsoApxbBF/MnuSVK4TCVb/62tYuMbybVnCoSINEOV+g+KeL 3CJceMXV0PEVigouqKPDSudQnV1scVsRC4D4ztIjNzY3zpjJ7joWFi+Vgs0ZtvyZTJXp StcQ== MIME-Version: 1.0 X-Received: by 10.152.21.106 with SMTP id u10mr5466847lae.11.1368107558359; Thu, 09 May 2013 06:52:38 -0700 (PDT) Received: by 10.112.202.137 with HTTP; Thu, 9 May 2013 06:52:38 -0700 (PDT) In-Reply-To: <518BA237.3030700@gmail.com> References: <518BA237.3030700@gmail.com> Date: Thu, 9 May 2013 14:52:38 +0100 Message-ID: Subject: Re: recommended memory for zfs From: Tom Evans To: Benjamin Adams Content-Type: text/plain; charset=UTF-8 Cc: freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 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, 09 May 2013 13:52:40 -0000 On Thu, May 9, 2013 at 2:18 PM, Benjamin Adams wrote: > Hello zfs question about memory. > I heard zfs is very ram hungry. > Service looking to run: > - nginx > - postgres > - php-fpm > - python > > I have a machine with two quad core cpus but only 4 G Memory > > I'm looking to buy more ram now. > What would be the recommend amount of memory for zfs across 6 drives on this > setup? > There is no right answer to this question. ZFS does not use a lot of RAM, but it will use as much as you allow as cache (in the ARC). How much data is your working set? How much of your working set do you need to keep in cache? You need that much memory (plus whatever to run your applications). > > Also can 9.1 now boot to zfs from the installer? > (no tricks for post install) > Can you clarify? The installer still cannot setup zfs pools, you must do so manually (but then can return to the installer). Cheers Tom