From owner-freebsd-fs@FreeBSD.ORG Wed Jul 17 01:47:54 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id B25F7CB1 for ; Wed, 17 Jul 2013 01:47:54 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (wonkity.com [67.158.26.137]) by mx1.freebsd.org (Postfix) with ESMTP id 532EEBD5 for ; Wed, 17 Jul 2013 01:47:54 +0000 (UTC) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.14.7/8.14.7) with ESMTP id r6H1lrRE084549; Tue, 16 Jul 2013 19:47:53 -0600 (MDT) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.14.7/8.14.7/Submit) with ESMTP id r6H1lrCT084546; Tue, 16 Jul 2013 19:47:53 -0600 (MDT) (envelope-from wblock@wonkity.com) Date: Tue, 16 Jul 2013 19:47:53 -0600 (MDT) From: Warren Block To: =?ISO-8859-15?Q?Gezeala_M=2E_Bacu=F1o_II?= Subject: Re: Slow resilvering with mirrored ZIL In-Reply-To: Message-ID: References: <51D42107.1050107@digsys.bg> <2EF46A8C-6908-4160-BF99-EC610B3EA771@alumni.chalmers.se> <51D437E2.4060101@digsys.bg> <20130704000405.GA75529@icarus.home.lan> <20130704171637.GA94539@icarus.home.lan> <2A261BEA-4452-4F6A-8EFB-90A54D79CBB9@alumni.chalmers.se> <20130704191203.GA95642@icarus.home.lan> <43015E9015084CA6BAC6978F39D22E8B@multiplay.co.uk> <3CFB4564D8EB4A6A9BCE2AFCC5B6E400@multiplay.co.uk> <51D6A206.2020303@digsys.bg> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="3512871622-1111948915-1374025673=:84500" X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (wonkity.com [127.0.0.1]); Tue, 16 Jul 2013 19:47:53 -0600 (MDT) Cc: FreeBSD Filesystems X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Jul 2013 01:47:54 -0000 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --3512871622-1111948915-1374025673=:84500 Content-Type: TEXT/PLAIN; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 8BIT On Tue, 16 Jul 2013, Gezeala M. Bacuņo II wrote: > On Fri, Jul 5, 2013 at 6:08 PM, Freddie Cash wrote: > >> >> ZFS- on-Linux has added this as "-o ashift=" property for zpool create. >> >> There's a threat on the illumos list about standardising this s across all >> ZFS- using OSes. >> >> >> > +1 on this. We tested zfs-on-linux last year and it does automatically > handle disk partitioning for correct alignment. What we do is just add > ashift=12 option during zpool create. No more gpart/gnop/ashift/import > steps. > > http://zfsonlinux.org/faq.html#HowDoesZFSonLinuxHandlesAdvacedFormatDrives > > > Back to FreeBSD ZFS, > > After reading the thread, I'm still at a loss on this (too much info I > guess).. regarding gpart/gnop/ashift tweaks for alignment, do we still need > to perform gpart on newly purchased (SSD/SATA/SAS) Advanced Format drives? > Or, skip gpart and proceed with gnop/ashift only? If ZFS goes on a bare drive, it will be aligned by default. If ZFS is going in a partition, yes, align that partition to 4K boundaries or larger multiples of 4K, like 1M. The gnop/ashift workaround is just to get ZFS to use the right block size. So if you don't take care to get partition alignment right, you might end up using the right block size but misaligned. And yes, it will be nice to be able to just explicitly tell ZFS the block size to use. --3512871622-1111948915-1374025673=:84500--