From owner-freebsd-questions@FreeBSD.ORG Fri Jul 18 08:48:25 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8CDA610D for ; Fri, 18 Jul 2014 08:48:25 +0000 (UTC) Received: from mail-yk0-x22e.google.com (mail-yk0-x22e.google.com [IPv6:2607:f8b0:4002:c07::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4EED42A9D for ; Fri, 18 Jul 2014 08:48:25 +0000 (UTC) Received: by mail-yk0-f174.google.com with SMTP id q9so1993156ykb.5 for ; Fri, 18 Jul 2014 01:48:24 -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:content-type; bh=U5CcLnPG22QeVITm+YkuL/gUp71JM961VnBFb8JyOk4=; b=qAVYZc52BJaFFXxWTnyYxENwfGKh91rzhFYTSfHGt6U4VxpYHFBYEe/WkQWCB9Vk1o vAH1rc846IU1tKjDyniP92Zg4tQy4hXQYOxj3Ziql+fsLOu3gFkPNak+fuJKFU4Vcrf1 sr0R5r1Ll8DlJDWTpFOgCwNiPUAe8JDWuCS2r0JL8C2nIoI9RxsT5PoTef4gQ/Mb7Zcq CmvhMCCcGrZ3UbJNZ/9wrGuIXT1QPXo1eviXrsTLNSRjW9yla5tFGiEL2uMVNZnxWouk HUcz5Eg+5PhEbCAf9dFr3oiwAYigPCJKtTJYePCuLdpk4OEYuT8cWjr7+7Cr55BlLZ3H Z4Iw== MIME-Version: 1.0 X-Received: by 10.236.108.147 with SMTP id q19mr5222079yhg.27.1405673304292; Fri, 18 Jul 2014 01:48:24 -0700 (PDT) Received: by 10.170.132.80 with HTTP; Fri, 18 Jul 2014 01:48:24 -0700 (PDT) In-Reply-To: <20140716143929.74209529@gumby.homeunix.com> References: <20140713190308.GA9678@bewilderbeast.blackhelicopters.org> <20140714071443.42f615c5@X220.alogt.com> <53C326EE.1030405@my.hennepintech.edu> <20140714111221.5d4aaea9@X220.alogt.com> <20140715143821.23638db5@gumby.homeunix.com> <20140716143929.74209529@gumby.homeunix.com> Date: Fri, 18 Jul 2014 09:48:24 +0100 Message-ID: Subject: Re: deciding UFS vs ZFS From: krad To: RW Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18 Cc: FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jul 2014 08:48:25 -0000 "I don't understand why you think that. My point was that losing random files from everything can be far more disruptive than losing files from a single mountpoint." Well thats why you would use copies=1+n one each dataset that was on a single drive. That way you wouldnt lose anything. If your that worried about drive failures though you should be using some kind of raid. "I was really more interested in whether ZFS (with ARC) is faster than UFS with FreeBSD's own file caching. A lot of people say that putting an OS on SSD gives a significant speed-up. 16GB should be more than enough to keep the important system files in memory, so it sounds like smarter caching might be useful." If you want speed sure UFS is faster on the same machine, but thats because its doing less. In the real world I dont notice any performance penalty running zfs, but thats based on my workloads. Yes if i ran benchmarks I would see a difference, but im nowhere running at the limits of my hardware/software so its not an issue. Therefore I would rather have the extra layers of integrity that zfs supplies over ufs. I also try to base my decisions on based on fact, experiences of others and best practices. Dont get me wrong it can all go wrong with zfs, its just what are the odds compared with other file systems.