From owner-freebsd-stable@FreeBSD.ORG Thu Sep 11 09:06:08 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id E0C01762; Thu, 11 Sep 2014 09:06:08 +0000 (UTC) Received: from constantine.ingresso.co.uk (constantine.ingresso.co.uk [IPv6:2a02:b90:3002:e550::3]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A6658678; Thu, 11 Sep 2014 09:06:08 +0000 (UTC) Received: from dilbert.london-internal.ingresso.co.uk ([10.64.50.6] helo=dilbert.ingresso.co.uk) by constantine.ingresso.co.uk with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82 (FreeBSD)) (envelope-from ) id 1XS0KJ-000NSw-OK; Thu, 11 Sep 2014 09:06:03 +0000 Received: from petefrench by dilbert.ingresso.co.uk with local (Exim 4.84 (FreeBSD)) (envelope-from ) id 1XS0KJ-000Hhc-Lu; Thu, 11 Sep 2014 10:06:03 +0100 Date: Thu, 11 Sep 2014 10:06:03 +0100 To: se@freebsd.org, freebsd-stable@freebsd.org, ari@ish.com.au Subject: Re: getting to 4K disk blocks in ZFS References: <540FF3C4.6010305@ish.com.au> <54100258.2000505@freebsd.org> In-Reply-To: <54100258.2000505@freebsd.org> User-Agent: Heirloom mailx 12.4 7/29/08 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Pete French X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Sep 2014 09:06:09 -0000 > This may never hit you, but ZFS is built on the assumption, that it > cannot happen at all, which is no longer true with 4KB drives that > are used with ashift=9. Have just been reading this thread, and as people are suggesting moving ashift from 9 to 12, doesnt using use 512B drives with ahift=12 also violate this ? Or is it smart enough ot know that the underlying sectors are separate ? -pete.