From owner-freebsd-fs@freebsd.org Tue May 17 21:16:17 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 75680B3F456 for ; Tue, 17 May 2016 21:16:17 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-io0-x232.google.com (mail-io0-x232.google.com [IPv6:2607:f8b0:4001:c06::232]) (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 3D6FA1CE1 for ; Tue, 17 May 2016 21:16:17 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: by mail-io0-x232.google.com with SMTP id f89so40661181ioi.0 for ; Tue, 17 May 2016 14:16:17 -0700 (PDT) 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; bh=kkj1+UCBiYndbNrtv0GY52CycSb/yBIhTS5KmeN8Hno=; b=TIZhrcngAZYRJ6cGCDKupKT/vFj3s9R7uB56jomdtKCUgC8dGe9L9fuGF2VnedX2DT wEkocW6M/+DJKGNg/rVIw9PqRUd8F/mg38bDt/a5Q11S8I5XgfV19N0e8fcKu8V10jsz OQ0lZX5iLn7en0jcVVrS05F9n3TiMm+SCtn34NaAuFXCXiy7O6+LT5/S9FMHX/j5ynG8 FuIyEFLc7ZP5dr/8ACVQvRcbkdAPy3XwJ1uBrBfQWtzEMjmpO+D2jBWugLYlEmPiM91x OlZbsIgV6Q/SHwOPlkZQVvX/oj7lCpeqFCFt5czoS9wV82wmIo2fpA+9XCdw+hZCciWn r1OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc; bh=kkj1+UCBiYndbNrtv0GY52CycSb/yBIhTS5KmeN8Hno=; b=WDiT5D60qP/ukDGmfVfiADk6Plcxkycc12455MsACSU09zQY7iY2PRFUnLbJTR87VF 1C5L+bk6jvn/nSEk9OoRiiSF4mgpubyaeKGfOd7LOOoYNvoc/qBFgT08UV2i5Zlyvm4j AVvvE0mpg31Vt5lrBRA1/SN086q4WFsbiV/+0ujb0f00CtbwKQKcpy+JHoZquIqbE1El w40q2jBAOxBt/0fMTFiKWby58/OF6VZBA5xMaoc0AWNyLSt08jrsjo2UQDnZA9obGAUk jr/Qz5FtQLpLeJexXvZHkY6IB8ZHrTV9z4NJDhvV5xvOT2AAVlLDeugaW8gCrdHiYFps SRAw== X-Gm-Message-State: AOPr4FWVagn6ObPY5Fj7nNlVx/yeZbQ7/o+V7bKWLypXloDUY9PTizUyECHbFAh8C9LJreIsVLie13BjM8lmGA== MIME-Version: 1.0 X-Received: by 10.107.134.24 with SMTP id i24mr2716422iod.130.1463519776605; Tue, 17 May 2016 14:16:16 -0700 (PDT) Received: by 10.107.173.79 with HTTP; Tue, 17 May 2016 14:16:16 -0700 (PDT) In-Reply-To: References: <8441f4c0-f8d1-f540-b928-7ae60998ba8e@lexa.ru> <16e474da-6b20-2e51-9981-3c262eaff350@lexa.ru> <1e012e43-a49b-6923-3f0a-ee77a5c8fa70@lexa.ru> <86shxgsdzh.fsf@WorkBox.Home> Date: Tue, 17 May 2016 14:16:16 -0700 Message-ID: Subject: Re: ZFS performance bottlenecks: CPU or RAM or anything else? From: Freddie Cash To: Steven Hartland Cc: "Brandon J. Wandersee" , "freebsd-fs@freebsd.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.22 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 May 2016 21:16:17 -0000 On Tue, May 17, 2016 at 2:11 PM, Steven Hartland wrote: > Raidz is limited essential limited to a single drive performance > per dev for read and write while mirror is single drive performance for > write its number of drives for read. Don't forget mirror is not limited t= o > two it can be three, four or more; so if you need more read throughput yo= u > can add drives to the mirror. > > To increase raidz performance you need to add more vdevs. While this > doesn't have to be double i.e. the same vdev config as the first it > generally a good idea. > > Don't forget that while it rebalances write performance of a multi vdev > raidz will be limited to the added vdev. > =E2=80=8BEverybody is missing the point of the OP. They're not asking for ways to improve the performance of a raidz-based pool; they're asking why they get different performance metrics from the exact same pool when they change the CPU and RAM. And, more importantly, why a Core-i3-based system shows better performance than a Core-i7-based system.=E2=80=8B Is there something inherent to the w= ay ZFS works that favours one setup over another (lower CPU core counts running at higher speeds is better/worse than higher CPU core counts running at lower speeds; more RAM channels is better/worse; things like that). --=20 Freddie Cash fjwcash@gmail.com