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 5C9331381F3 for ; Thu, 19 Sep 2013 12:29:42 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 29E8DE0BB3; Thu, 19 Sep 2013 12:29:38 +0000 (UTC) Received: from mail-qc0-f172.google.com (mail-qc0-f172.google.com [209.85.216.172]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 21508E0B52 for ; Thu, 19 Sep 2013 12:29:36 +0000 (UTC) Received: by mail-qc0-f172.google.com with SMTP id l13so5502675qcy.3 for ; Thu, 19 Sep 2013 05:29:36 -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 :content-type; bh=CHiRjMPLra8KMz3F3luC0QVBE21nA42x3mPYluTrcFk=; b=q/HqhDmauYU5CdAx28MmcWydvp7j6TDRgUO+br7Ic7wlMmo19kfoyFU1SEvd8r4OmC epHk2ax3D2C6SW5kmgHGrNYizyCZ8yAuxPRLFhjVow0mAAd88AjdrMLHsji77fIEhnaG PSN701RQlw3lBxluYligYupcDJU/tA2DCDuwHzC3bBrdu0KIL64r5cxV2FP77OLn5odx Lhdc/FwIW3iyJZ7S+KXdKS6I4qBTKQhA7TZwmbs80jOl28GSaTwdv2zkAv5pnpEmiMlS hBhKP7bkHvbgc5imYt6LjA1G+oATZvZyB8JvyTQsTILRPZvIVa48Cxxi4piV8tSwSLWJ M6Dg== 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 10.49.96.225 with SMTP id dv1mr2742266qeb.89.1379593775485; Thu, 19 Sep 2013 05:29:35 -0700 (PDT) Received: by 10.140.25.83 with HTTP; Thu, 19 Sep 2013 05:29:35 -0700 (PDT) In-Reply-To: <523AD3F2.40301@libertytrek.org> References: <523898A3.7000404@googlemail.com> <52389B55.6090600@libertytrek.org> <20130918042228.GG25579@server> <20130919074441.GB12275@TranscendTheRubicon.fritz.box> <523AD3F2.40301@libertytrek.org> Date: Thu, 19 Sep 2013 12:29:35 +0000 Message-ID: Subject: Re: [gentoo-user] Re: ZFS From: Grant To: Gentoo mailing list Content-Type: text/plain; charset=ISO-8859-1 X-Archives-Salt: 890de90f-480f-4124-875f-4f876f961cd9 X-Archives-Hash: a537ab1d61ac3f84a5ccabc7252d8d6a >> You should definitely determine the right value for ashift on pool >> creation >> (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 >> have >> drives requiring different alignments[1]) >> If in doubt: ask ryao (iirc given the right information he can tell you >> which >> are the right options for you if you can't deduce it yourself). >> Choosing the wrong alignment can cause severe performance loss (that's not >> a ZFS issue but happened when 4k sector drives appeared and tools like >> fdisk >> weren't aware of this). > > Yikes... > > Ok, shouldn't there be a tool or tools to help with this? Ie, boot up on a > bootable tools disk on the system with all drives connected, then let it > 'analyze' your system, maybe ask you some questions (ie, how you will be > configuring the drives/RAID, etc), then spit out an optimized config for > you? I'm also interested to know the procedure for getting this right. > It is starting to sound like you need to be a dang engineer just to use > ZFS... I thought the SSD issue was completely separate from ZFS and applicable to any other filesystem as well. Someone please correct me if I'm wrong. - Grant