From owner-freebsd-questions@FreeBSD.ORG Fri Jun 19 15:37:45 2015 Return-Path: Delivered-To: freebsd-questions@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1A98C5F7 for ; Fri, 19 Jun 2015 15:37:45 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from cosmo.uchicago.edu (cosmo.uchicago.edu [128.135.70.90]) by mx1.freebsd.org (Postfix) with ESMTP id E91DAEB9 for ; Fri, 19 Jun 2015 15:37:44 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: by cosmo.uchicago.edu (Postfix, from userid 48) id 46D8FCB8C9C; Fri, 19 Jun 2015 10:37:38 -0500 (CDT) Received: from 128.135.70.2 (SquirrelMail authenticated user valeri) by cosmo.uchicago.edu with HTTP; Fri, 19 Jun 2015 10:37:38 -0500 (CDT) Message-ID: <44429.128.135.70.2.1434728258.squirrel@cosmo.uchicago.edu> In-Reply-To: <1434726141.6154.34.camel@michaeleichorn.com> References: <557F90DB.80601@herveybayaustralia.com.au> <5583D5BE.7050508@herveybayaustralia.com.au> <1434726141.6154.34.camel@michaeleichorn.com> Date: Fri, 19 Jun 2015 10:37:38 -0500 (CDT) Subject: Re: ZFS passdevgonecb From: "Valeri Galtsev" To: "Michael B. Eichorn" Cc: "Da Rock" , freebsd-questions@freebsd.org Reply-To: galtsev@kicp.uchicago.edu User-Agent: SquirrelMail/1.4.8-5.el5.centos.7 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Jun 2015 15:37:45 -0000 On Fri, June 19, 2015 10:02 am, Michael B. Eichorn wrote: > > On Fri, 2015-06-19 at 18:41 +1000, Da Rock wrote: >> Ok, top posting as a summary really - numerous threads of thought going >> on now. > There are a few levels of drives these days. There are the enterprise > grade > drives that can take a bit more heat and have a longer mean time to > failure. > These drive have tighter manufacturing tolerances and cost lots more. Then > there > are NAS/RAID consumer drives that are made to about the same tolerances as > a > desktop drive but have a few modifications for a 24/7 workload. Typical > desktop > drives are not actually designed for 24/7 operation. > > Then there is the firmware, some drives designed for 'green-ness' try to > spin > down and do other things to save power, with a typical Windows desktop > this is > probably good. However zfs (and most raids) expect the drive to do > nothing > without being told since zfs knows more than any firmware could. > > Frankly for most small-business and home loads WD Red Drives + zfs is > enough for > servers. I don't even put spinning rust in desktops anymore SSD + a > network > drive is enough for non-workstation tasks. > I would endorse all you said about drives. I will just mention the "consumer" grade drives I happily use in RAIDs that proven to be very reliable: Hitachi (these days HGST) SATA 7200 rpm. (And as it was already mentioned, stay away from "green" "spin-down" and low 5400 rpm 3.5 inch drives). Just my $0.02. Valeri ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++