From owner-freebsd-fs@FreeBSD.ORG Sat Feb 8 10:03:01 2014 Return-Path: Delivered-To: freebsd-fs@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 7EC92158 for ; Sat, 8 Feb 2014 10:03:01 +0000 (UTC) Received: from mail-vc0-x22b.google.com (mail-vc0-x22b.google.com [IPv6:2607:f8b0:400c:c03::22b]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 37FD41C99 for ; Sat, 8 Feb 2014 10:03:01 +0000 (UTC) Received: by mail-vc0-f171.google.com with SMTP id le5so3424267vcb.16 for ; Sat, 08 Feb 2014 02:02:59 -0800 (PST) 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=0jUgPO7DEsdEOmsDeD7DbxZkKMcISPnxXTk8MeJVK8Q=; b=dcvX6e8dICHG2ahho+yASLqMO49DUMZTggM5NOBClDUUWd10B2a79XSinCCe4F/06Z IPstJSqub316ORKfCUSosGpYhNVnl5qmORKd171HDX4hOvjZLygOngnftRZJD3Wbngbi F/mavYY1aQqda0fldSe+grYZcmZwpb9LZu+HufGx/f0Tw0cDACYv5oSd1nHLMteMWgJR EykFpXZCwu+xzqR12iWoQSKBHhzJfHHaSD2+6OPQuRZSkNPnBavVMHmjx659AEh6oOeZ NqsiTY78J4dC6RVQ32c+5VOrYO0FeyZCPNYfrjmi/xRKC5ynS/uoNThR5oBREpyjmDAf Dmtw== MIME-Version: 1.0 X-Received: by 10.220.191.134 with SMTP id dm6mr14609710vcb.16.1391853779287; Sat, 08 Feb 2014 02:02:59 -0800 (PST) Received: by 10.58.128.132 with HTTP; Sat, 8 Feb 2014 02:02:59 -0800 (PST) In-Reply-To: <878utmxtum.wl%berend@pobox.com> References: <1487AF77-7731-4AF8-8E44-FF814BB8A717@ebureau.com> <1391808195.4799.80708189.5CAD8A4E@webmail.messagingengine.com> <8B5D8D0C-ADDE-49B3-87A9-DE1105E32BF9@ebureau.com> <878utmxtum.wl%berend@pobox.com> Date: Sat, 8 Feb 2014 11:02:59 +0100 Message-ID: Subject: Re: Using the *real* sector/block size of a mass storage device for ZFS From: Johan Hendriks To: Berend de Boer Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: "" X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 08 Feb 2014 10:03:01 -0000 Op zaterdag 8 februari 2014 heeft Berend de Boer het volgende geschreven: > >>>>> "Dustin" == Dustin Wenz > > writes: > > Dustin> Am I correct in assuming that it is absolutely impossible > Dustin> to convert an existing ashift:9 vdev to ashift:12? Some of > Dustin> my pools are approaching 1PB in size; transferring the > Dustin> data off and back again would be inconvenient. > > I thought you could do it one disk at a time (if you have a redundant > pool). > > But maybe not. > > -- > All the best, > > Berend de Boer No that is not possible. The ashift is set when the pool is created, hence the fact that you only need the gnop method at pool creation time. If you add a vdev to the pool you do not need the gnop method anymore because you can not change it. You can align the disk so it has a 4 k alignement. But that is not the ashift of the pool I think FreeBSD 10 sees if the disk is capable for a ashift of 12 and therefor give you a warning. I have a FreeBSD 10 machine with two types of disks. WD RE and WD SE drives. If i create a pool with the RE drives, FreeBSD 10 will create it with a ashift of 9, so i need to use the gnop method to get a ashift of 12. If i create a pool with the SE drives, it automaticly uses a ashift of 12. I guess if i did create the pool with the SE drives on FreeBSD 9 with a ashift of 9 FreeBSD 10 would warn me with the warning you see. I use gpart to create a 4k disk alignement. # gpart create -s gpt da0 # gpart add -a 4k -t freebsd-zfs -l labelname da0 This way the disk has a 4k alignement. To get a asift of 12 on your pool you can use the gnop method, or you could try to create the pool without gnop and see if FreeBSD 10 detect the disk as a advanced format disk as it does for the WD SE drives, that way you do not need the gnop method. If FreeBSD 10 gives you a this warning, i am almost certain you do not need the gnop method on those disks. Regards Johan Hendriks