From owner-freebsd-fs@freebsd.org Mon Nov 9 20:07:44 2015 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 46262A2A608 for ; Mon, 9 Nov 2015 20:07:44 +0000 (UTC) (envelope-from tjg@ucsc.edu) Received: from mail-lb0-x233.google.com (mail-lb0-x233.google.com [IPv6:2a00:1450:4010:c04::233]) (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 CAD0B1F9C for ; Mon, 9 Nov 2015 20:07:43 +0000 (UTC) (envelope-from tjg@ucsc.edu) Received: by lbbcs9 with SMTP id cs9so1588887lbb.1 for ; Mon, 09 Nov 2015 12:07:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucsc.edu; s=ucsc-google; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=1d+PJqmQd3bQM27ww1hENRZzzKCsS8eK6k9zu54C1ZA=; b=K5u1KG5KMQHQEnm6D7v8F2HDzm1XAs9O1bn77bEZLbDxOrGe48qLjrKCD3Xa7un9yw BgbFDCnWGLp5oo7e+oSEk1DOaGlqHNtXYbP9g7k1qFbTpqc8p5G8iC+lI5iR6vSKpd0p iid8iKaMVaZtCPPRyr0of3rF2Zka80Xnp9MDQ= 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:content-type; bh=1d+PJqmQd3bQM27ww1hENRZzzKCsS8eK6k9zu54C1ZA=; b=RSuhzmHHgDJiGyONyLzkM/2/nE/a46BuntPKIpA3y1TxRydbpWRz1AI7KGVAmwyQQu VT1tXKk2cte/7hWxgDskuZ2ffxxlbv0xo7AmhSQiPB5eX7CobhuLrZCyqSj++FM/NqLS NZ74urpepFWOiFlqH+CL1znH4vkUXKMVsl0bV6xUweobR13m9WfQTA1C/KDTdr15Py21 4IhwR0fSvCbj02yuxOiHDvpyphLnWrd+TqiG0OmnLnuO3S6L0NVwSHeToAkeqq0ZphH6 ZWE2omJFKY7s5LkVUtMRMVKzevc5vVBm7RqH6mkPlNm1mVk73dEytaZXaHpa2lyOY/WA LKGA== X-Gm-Message-State: ALoCoQkNw/OCkqtV8WhoOmNw+Ort49ryB9KbYK1Cu1XHGvDtKQZU0yLwwV8gJpNbOj49GA+EQedV MIME-Version: 1.0 X-Received: by 10.112.11.163 with SMTP id r3mr14912479lbb.8.1447099661554; Mon, 09 Nov 2015 12:07:41 -0800 (PST) Received: by 10.25.205.16 with HTTP; Mon, 9 Nov 2015 12:07:41 -0800 (PST) In-Reply-To: References: Date: Mon, 9 Nov 2015 12:07:41 -0800 Message-ID: Subject: Re: ZFS RAID 0+1 Throwing Checksum Errors From: Tim Gustafson To: Sean Chittenden Cc: freebsd-fs@freebsd.org Content-Type: text/plain; charset=UTF-8 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: Mon, 09 Nov 2015 20:07:44 -0000 > It could be the SSDs, the controller, cables, or power supply. > The problem might occur when the data is written, or when it is > read back. If this is occuring on all of the SSDs then look for > some shared component which might be causing the problem. I'll check into these possibilities. Now that I think of it, I should check to see of the Perc card has its own log that I could look at, even though we're not using its RAID features. > Tim, I've run into this a dozen or so times on servers where their > power is "dirty" (i.e. home or small offices with small servers that > use ZFS). If you plug the box into a UPS to condition the line you > may find that the checksum errors go away. It's pretty amazing > to see and happens with both SSD and spinning rust. It's not > always the case, but it's a common enough environmental problem. > Report back if you try this and it solves your problem. I'm pretty sure that's not the case. This server is a new-ish (3 months old?) Dell R630 with redundant power supplies, connected to an industrial APC UPS, connected to an industrial diesel backup generator, housed in a real bone-fide server room with industrial cooling. There's about 80 other physical servers in this room room, and none of the others are exhibiting this behavior. -- Tim Gustafson Technical Lead, Baskin School of Engineering tjg@ucsc.edu 831-459-5354 Baskin Engineering, Room 313A