From owner-freebsd-fs@freebsd.org Sun Mar 6 14:48:58 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 E0471AC08AE for ; Sun, 6 Mar 2016 14:48:57 +0000 (UTC) (envelope-from richard.elling@richardelling.com) Received: from mail-pf0-x230.google.com (mail-pf0-x230.google.com [IPv6:2607:f8b0:400e:c00::230]) (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 B611ED7 for ; Sun, 6 Mar 2016 14:48:57 +0000 (UTC) (envelope-from richard.elling@richardelling.com) Received: by mail-pf0-x230.google.com with SMTP id 63so64052518pfe.3 for ; Sun, 06 Mar 2016 06:48:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=richardelling.com; s=google; h=from:mime-version:subject:in-reply-to:date:cc:message-id:references :to; bh=bbzXCrDE6syxSdN4o9Ccw/KWeGKeKT1V1RnlzODgOeU=; b=aBcRt9PKAWh0DEtXL1rJ/C1wmJGBYv0yhbhmcu6CCJZw4OHcrLEl93VPjATK80Q2iv Zii92g4Wwl8xsAXmWanK28f6gZ8BG2yag4xJbvXgWGw9DrGKgJan0TRwlyfletci6F/U p2n6qCTvsfHlbAE/FKM+AGk1S+Ajs8HiNJxPQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:mime-version:subject:in-reply-to:date:cc :message-id:references:to; bh=bbzXCrDE6syxSdN4o9Ccw/KWeGKeKT1V1RnlzODgOeU=; b=j+08m5d1T5tXor9jfLJTGqxym+W2mI7Qe2EnGTI6jMYa33t8opW7MosaPEutal+b32 CqYpOBXPNB6DKAqOpQsJ/8incriLf6dxY+qRjmtvyLC4KOTo88llJraUjmsD5fC9csnb WD0vK1WRNHcyY+NMbzg9juDOEtMa3OgF4+gR/ZGEyaGSKpS2PiW8wjUzv67cqruJFwl9 5yWgs39JGCfqvCsG4IyLv/qb5qAGP+vMpiG0Q4FeMYg3869VXz++vP4nG1P2N8u0/7Ef PAFKb0iL7RI5aF+fvzjhDOQyN77QkGEhh4Aujeg/A0OdrCPSAgl6Y5Q2BDvLNgH7ZIlo 3S1g== X-Gm-Message-State: AD7BkJLBr+R+iCzs/bPfOs/UjhDBSW9tXL68yfhG+JJ+4+VsNBgYeEWFPQtZg2rHBE1U2Q== X-Received: by 10.98.7.11 with SMTP id b11mr26986582pfd.38.1457275737079; Sun, 06 Mar 2016 06:48:57 -0800 (PST) Received: from [192.168.129.105] ([162.250.162.10]) by smtp.gmail.com with ESMTPSA id e79sm18206855pfb.76.2016.03.06.06.48.55 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 06 Mar 2016 06:48:56 -0800 (PST) From: Richard Elling X-Google-Original-From: Richard Elling Mime-Version: 1.0 (Mac OS X Mail 9.2 \(3112\)) Subject: Re: [smartos-discuss] an interesting survey -- the zpool with most disks you have ever built In-Reply-To: Date: Sun, 6 Mar 2016 06:49:36 -0800 Cc: developer , "developer@lists.open-zfs.org" , illumos-developer , omnios-discuss , Discussion list for OpenIndiana , illumos-zfs , "zfs-discuss@list.zfsonlinux.org" , "freebsd-fs@FreeBSD.org" , "zfs-devel@freebsd.org" Message-Id: <5158F354-9636-4031-9536-E99450F312B3@RichardElling.com> References: <95563acb-d27b-4d4b-b8f3-afeb87a3d599@me.com> <56D87784.4090103@broken.net> To: smartos-discuss@lists.smartos.org X-Mailer: Apple Mail (2.3112) X-Mailman-Approved-At: Sun, 06 Mar 2016 15:11:00 +0000 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.21 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Mar 2016 14:48:58 -0000 > On Mar 3, 2016, at 8:35 PM, Fred Liu wrote: >=20 > Hi, >=20 > Today when I was reading Jeff's new nuclear weapon -- DSSD D5's CUBIC = RAID introduction, > the interesting survey -- the zpool with most disks you have ever = built popped in my brain. We test to 2,000 drives. Beyond 2,000 there are some scalability issues = that impact failover times. We=E2=80=99ve identified these and know what to fix, but need a real = customer at this scale to bump it to the top of the priority queue. >=20 > For zfs doesn't support nested vdev, the maximum fault tolerance = should be three(from raidz3). Pedantically, it is N, because you can have N-way mirroring. > It is stranded if you want to build a very huge pool. Scaling redundancy by increasing parity improves data loss protection by = about 3 orders of=20 magnitude. Adding capacity by striping reduces data loss protection by = 1/N. This is why there is not much need to go beyond raidz3. However, if you do want to go there, = adding raidz4+ is=20 relatively easy. =E2=80=94 richard -- Richard.Elling@RichardElling.com +1-760-896-4422