From owner-freebsd-fs@freebsd.org Tue Jan 5 03:40:23 2016 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 991FDA616C6 for ; Tue, 5 Jan 2016 03:40:23 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-wm0-x22b.google.com (mail-wm0-x22b.google.com [IPv6:2a00:1450:400c:c09::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 36F001E0E for ; Tue, 5 Jan 2016 03:40:23 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: by mail-wm0-x22b.google.com with SMTP id f206so8022830wmf.0 for ; Mon, 04 Jan 2016 19:40:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=x4PPxEAwYSAQPQIf5KWB/4KJZNyYruMcWQoT/LLn9cM=; b=0gC9Dez+qO6394XyIlrtOaCslZwQPbpxU5zJOtewa2tYLWIs3rfUfkNDcurfqT5ZBW nzbeEXt/lKTAgdFNbtOvbi8mtqujU3O1/WkKcy0VhoLXdDFAzkE1FNegX+OePq7eko9D 18LgtWGDbRlTnsKktvdInI1EXLFuIWhWQnDhZKOSsstPSd6tZkX0TOiJrVgzzUgJgAgp 0VduffYvl+og+V3ffPelydcsgzzk7YhTsgyshMuyP//AoJFxeaU5/pgLb4qQAFBYG+lw aNRJj6mWOorBC2x9oc52LG47FPG4PKfVZOItHcPf0P81Mnanr3kDDi5HlnZfhKxroxVQ d24g== MIME-Version: 1.0 X-Received: by 10.28.63.200 with SMTP id m191mr1710581wma.67.1451965220653; Mon, 04 Jan 2016 19:40:20 -0800 (PST) Received: by 10.194.192.33 with HTTP; Mon, 4 Jan 2016 19:40:20 -0800 (PST) In-Reply-To: References: <8291bb85-bd01-4c8c-80f7-2adcf9947366@email.android.com> <5688D3C1.90301@aldan.algebra.com> <495055121.147587416.1451871433217.JavaMail.zimbra@uoguelph.ca> <568A047B.1010000@aldan.algebra.com> Date: Mon, 4 Jan 2016 21:40:20 -0600 Message-ID: Subject: Re: NFS reads vs. writes From: Adam Vande More To: Paul Kraus Cc: FreeBSD Filesystems , "Mikhail T." Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Jan 2016 03:40:23 -0000 On Mon, Jan 4, 2016 at 9:06 PM, Paul Kraus wrote: > I have a file server that I am going through the task of optimizing for > NFS traffic (to store VM images). My first attempt, because I knew about > the need for an SSD based SLOG for the ZIL was using a pair of Intel 535 > series SSD=E2=80=99s. The performance with the SLOG/ZIL on the SSD was _w= orse_. > Turns out that those SSD=E2=80=99s have poor small block (8 KB) random wr= ite > performance (not well advertised). So I asked for advice for choosing a > _fast_ SSD on the OpenZFS list and had a number of people recommend the > Intel DC-Sxxxx series of SSDs. > > Based on the very thorough data sheets, I am going with a pair of DC-S371= 0 > 200 GB SSDs. Once I get them in and configured I=E2=80=99ll post results. > > Note that my zpool consists of 5 top level vdevs each made up of a 3-way > mirror. So I am striping writes across 5 columns. I am using 500 GB WD RE > series drives leaving the ZIL on the primary vdevs was _faster_ than addi= ng > the consumer SSD as SLOG for NFS writes Something like zeusram or ddrdrive is probably going to yield the most preformant solution for zfs sync writes. --=20 Adam