From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 64A741381F3 for ; Thu, 19 Sep 2013 07:47:58 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id F2767E0C76; Thu, 19 Sep 2013 07:47:49 +0000 (UTC) Received: from svr-us4.tirtonadi.com (svr-us4.tirtonadi.com [69.65.43.212]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id DECE7E0C87 for ; Thu, 19 Sep 2013 07:47:48 +0000 (UTC) Received: from mail-vb0-f41.google.com ([209.85.212.41]:42675) by svr-us4.tirtonadi.com with esmtpsa (TLSv1:RC4-SHA:128) (Exim 4.80.1) (envelope-from ) id 1VMYxq-000T1G-0V for gentoo-user@lists.gentoo.org; Thu, 19 Sep 2013 14:47:50 +0700 Received: by mail-vb0-f41.google.com with SMTP id g17so6352750vbg.28 for ; Thu, 19 Sep 2013 00:47:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; bh=RHr1YjwKHUtCjr7q4BFcXPprBfpfqV5Mtxnz79rJhCo=; b=ak+zokwN8buJcPM3gAteZ2jhgsN9OqXQ2VxzWX2oQZkBSU1MrwHiNdjIAUvdR4J+tf +kd18Qh+MWII+Hr6gd7uMVNrGtgUQpK/sKtlHrPxBRJPljqGqCBfus2he5mLOcDpJX0v kDE/Stg12mtK6pBKvIaJN1gyUzNO8hjlXpU7/VP16eTAWmGBtE1hWOEjl6J9beM712wT iK5Z6AtIyv58nM9CUJOV2/CqMNiokp/YgWxGZUX8VNFFVPdRSVRIiR5OVQBMMxfTR1J7 2DiXemf2oaMwvGplFHF2ObGobvgy3EkcTyaPiNz7EayMTyIiWNXp6oBP8UjgUz/wWqDo dGwg== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 X-Received: by 10.52.227.6 with SMTP id rw6mr49443vdc.19.1379576867955; Thu, 19 Sep 2013 00:47:47 -0700 (PDT) Received: by 10.220.163.69 with HTTP; Thu, 19 Sep 2013 00:47:47 -0700 (PDT) In-Reply-To: <20130919074441.GB12275@TranscendTheRubicon.fritz.box> References: <523898A3.7000404@googlemail.com> <52389B55.6090600@libertytrek.org> <20130918042228.GG25579@server> <20130919074441.GB12275@TranscendTheRubicon.fritz.box> Date: Thu, 19 Sep 2013 14:47:47 +0700 Message-ID: Subject: Re: [gentoo-user] Re: ZFS From: Pandu Poluan To: gentoo-user Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - svr-us4.tirtonadi.com X-AntiAbuse: Original Domain - lists.gentoo.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - poluan.info X-Get-Message-Sender-Via: svr-us4.tirtonadi.com: authenticated_id: rileyer+pandu.poluan.info/only user confirmed/virtual account not confirmed X-Archives-Salt: ff79c0b5-c4a3-4d0b-aee9-d203fdbfdc95 X-Archives-Hash: 56116dd657908d6c1e50b341a689ec6a On Thu, Sep 19, 2013 at 2:44 PM, Hinnerk van Bruinehsen wrote: > On Wed, Sep 18, 2013 at 09:49:40PM -0700, Grant wrote: >> > I think many folks are interested in upgrading to EXT4 with RAID from >> > an ordinary JBOD workstation(server); or better yet to ZFS on RAID. I = wish >> > one of the brighter minds amongst us would put out a skeleton >> > (wiki) information page as such: >> > >> > http://wiki.gentoo.org/wiki/ZFS+RAID >> > >> > I know I have struggled with completing this sort of installation >> > several time in the last 6 months. I'm sure this (proposed) wiki page >> > would get lots of updates from the Gentoo user community. Surely, >> > I'm not qualified to do this, or it would have already been on the >> > gentoo wiki.... >> > >> > Much of the older X + RAID pages are deprecated, when one considers >> > the changes that accompany such an installation ( Grub2, UUID, fstab, >> > partitioning of drives, Kernel options, just to name a few). We're >> > talking about quite a bit of deviation from the standard handbook >> > installation, fraught with hidden, fatal mis-steps. >> >> Any important points or key concepts a ZFS newbie should remember when >> installing with it for the first time? >> >> - Grant > > > You should definitely determine the right value for ashift on pool creati= on > (it controls the alignment on the medium). It's an option that you afaik = can only set > on filesystem creation and therefore needs a restart from scratch if you = get it > wrong. > According to the illumos wiki it's possible to run a mixed pool (if you h= ave > drives requiring different alignments[1]) > If in doubt: ask ryao (iirc given the right information he can tell you w= hich > are the right options for you if you can't deduce it yourself). > Choosing the wrong alignment can cause severe performance loss (that's no= t > a ZFS issue but happened when 4k sector drives appeared and tools like fd= isk > weren't aware of this). > > WKR > Hinnerk > Especially with SSDs. One must find out the blocksize used by his/her SSDs. With spinning disks, setting ashift=3D12 is enough since no spinning disks have sectors larger than 2^12 bytes. With SSDs, one might have to set ashift=3D13 or even ashift=3D14. Rgds, --=20 FdS Pandu E Poluan ~ IT Optimizer ~ =E2=80=A2 LOPSA Member #15248 =E2=80=A2 Blog : http://pepoluan.tumblr.com =E2=80=A2 Linked-In : http://id.linkedin.com/in/pepoluan