From owner-freebsd-arch@FreeBSD.ORG Fri Dec 25 11:27:43 2009 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0EA2A10656A4; Fri, 25 Dec 2009 11:27:43 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-fx0-f227.google.com (mail-fx0-f227.google.com [209.85.220.227]) by mx1.freebsd.org (Postfix) with ESMTP id 6AA618FC1B; Fri, 25 Dec 2009 11:27:42 +0000 (UTC) Received: by fxm27 with SMTP id 27so8788129fxm.3 for ; Fri, 25 Dec 2009 03:27:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=wkz+a8gEXMEDZkF74xrcCKTqK2ep/dI9sOSVAH0mAs8=; b=JWU99z8Z6Q+WNtUvChyGlbjrkNoEHbLPbgiPjKFUGuMOllANhI7SoKq18kbX6gG6pz b8dXdzPU0PZtkZf4r3DAEJAR0hYwdXeuNLsmYhELaAPV2/K9OgdpwTGMiLhBFZ7gjXU8 i66kRYzD2MA/AeDHQjGwIL/Ri30mL+IErhGm0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=Rd28odWfAhYh6BHS5lFK5sW841UQcOzXPCu6a255Vsvq9ECc7dZsOvJUKNGsd+HgEL M9X5NEuCs+kCkyOERr9GwppzMvY8+LhjwfXelzis/eJt+FHSfexxnJ90WrM2t5ByrCvL Axujpk5+JZPjLOBs7HwTAm2+ISeq/ewsxJn2w= Received: by 10.223.14.150 with SMTP id g22mr10842718faa.14.1261740461308; Fri, 25 Dec 2009 03:27:41 -0800 (PST) Received: from mavbook.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id 14sm3159895fxm.7.2009.12.25.03.27.39 (version=SSLv3 cipher=RC4-MD5); Fri, 25 Dec 2009 03:27:40 -0800 (PST) Sender: Alexander Motin Message-ID: <4B34A183.7000909@FreeBSD.org> Date: Fri, 25 Dec 2009 13:26:59 +0200 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20090901) MIME-Version: 1.0 To: Thomas Backman References: <4B349ABF.2070800@FreeBSD.org> <469FFFC8-514B-41B9-AEEC-E4B7AB6CB886@exscape.org> In-Reply-To: <469FFFC8-514B-41B9-AEEC-E4B7AB6CB886@exscape.org> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: FreeBSD-Current , freebsd-arch@freebsd.org Subject: Re: File system blocks alignment X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Dec 2009 11:27:43 -0000 Thomas Backman wrote: > On Dec 25, 2009, at 11:58 AM, Alexander Motin wrote: |>> Recently WD released first series of ATA disks with increased physical >> sector size. It makes writes not matching with 4K blocks inefficient >> there. > They don't expose this to the OS, though (not by default, anyway), but chop it up into 8 512-byte sectors for compatibility reasons. > Just thought I'd point that out - I'm not even sure if you can get them to *not* do the compatibility thing and expose 4k-sized sectors. Latest ATA-8 specification allows drive to report both logical (512B) and physical (4KB) sector sizes. ada driver able to fetch and report that info to GEOM. If these drives not reporting it yet (are you really sure?), it is only question of their firmware. -- Alexander Motin