From owner-freebsd-questions@FreeBSD.ORG Thu Jun 21 13:59:12 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 19D25106564A for ; Thu, 21 Jun 2012 13:59:12 +0000 (UTC) (envelope-from mgamsjager@gmail.com) Received: from mail-vc0-f182.google.com (mail-vc0-f182.google.com [209.85.220.182]) by mx1.freebsd.org (Postfix) with ESMTP id BB3298FC0C for ; Thu, 21 Jun 2012 13:59:11 +0000 (UTC) Received: by vcbfy7 with SMTP id fy7so409881vcb.13 for ; Thu, 21 Jun 2012 06:59:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=IDj7gnJSotS4j+GZbKOkJXT97/uoRO5Gdgs3s8Y0fbU=; b=NfbAIGgGOrb+NssPNizZYaXWzu3olUdv+o96nr8BBorApZ6i4J4sNV0IagaYGjPQL6 38ERVmi/Pm5O23erfJh6BROYvPFU/SF+jKE/0CLM51FW6jmf/JybmW0AkBqYckTXutnz vtrrrsDFrg7MfnRIZl/jePE2GND9gSm+JO+ykOFyBMUMF3XzJgJva4mPGFcdgJ1qffyB CNPRK8NEDUo4L6Iu3bgcbSLgZyh1hiq1c1AnMiZv1vhBZQgOHq2vepxeKKvFq1Ez/yui zDMddYZX25haKMx7RDlxFyCfFV9EA53r3KBVj86IeinBxJ+Br18s8Xa7bVRpE9M3iL8K O1PA== Received: by 10.52.21.229 with SMTP id y5mr11150292vde.68.1340287151167; Thu, 21 Jun 2012 06:59:11 -0700 (PDT) MIME-Version: 1.0 Received: by 10.220.172.199 with HTTP; Thu, 21 Jun 2012 06:58:40 -0700 (PDT) In-Reply-To: References: <4FE2CE38.9000100@gmail.com> From: Matthias Gamsjager Date: Thu, 21 Jun 2012 15:58:40 +0200 Message-ID: To: Wojciech Puchar Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Kaya Saman , FreeBSD Questions , Hooman Fazaeli Subject: Re: Is ZFS production ready? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Jun 2012 13:59:12 -0000 On Thu, Jun 21, 2012 at 3:43 PM, Wojciech Puchar < wojtek@wojtek.tensor.gdynia.pl> wrote: > I really want to see your face when you fsck 48TB w/o ffs+j (since that is >> so young must be immature :S ) of data with the phone ring non stop with >> > > Even if ZFS would be the only filesystem in existence i would make one per > 2 disks (single mirror). > > No matter what's going on, what do you prefer in case say - double disk > failure from one mirror on 48 disk systems? > > losing completely data of 1/24 of users (and then restoring that amount > from backups), or losing randomly chosen 1/24 of files from whole system? > > answer yourself. > Sorry but I don;t follow you right there. with 48 disks you would not mirror 24vs24. I will perform very well but there is too much risk in that. you would rather go with a raidz2 stripe sets. > > With UFS of course i would have single disk fsck time - less than a hour. > which CAN be done out of work hours with soft updates. > > i normally turn off automatic fsck for large data filesystems, and if > crash happened i run it after/before work hours. > > > raid is not a backup. You can loose data with any configuration or fs. so like in the compiler discussion. There is no perfect something in this world. It's always a tradeoff. with ZFS you have access to most advanced techniques and I believe that data is most safe with raidz3 as it can be. UFS cant match that and you have to rely on a raidcontroller which can screw up your data as well.