From owner-freebsd-stable@FreeBSD.ORG Sun Nov 3 23:30:57 2013 Return-Path: Delivered-To: freebsd-stable@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 ESMTP id 9B9C27F7 for ; Sun, 3 Nov 2013 23:30:57 +0000 (UTC) (envelope-from tom@samplonius.org) Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 732E329FC for ; Sun, 3 Nov 2013 23:30:57 +0000 (UTC) Received: by mail-pa0-f51.google.com with SMTP id ld10so6295893pab.10 for ; Sun, 03 Nov 2013 15:30:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=TF9VoPFZkuLZGIZLFEgnOLsWOYCxnoZkXQvkp8J4BZM=; b=b61vk1vZC4xWXSijue08ihOX4GwAn3R+SY5Jur8KpnlrWUM4K10OsYSU3wDJgnxMsH 0+MHonJ930JYXqaZpu2B8J8jYVmnXKv5PW354rhy6P/wO3AblgtJT1u1k6Ax6iLE1B6k 0OLZB5VAW/O+Q1mrxr0H6gvqoAS90MPBuawH73aoKV+e8D8y/J5Po3eov+E+voGYXVFd gVZF+i0lBxjgkhIzkcgr+M578Jvknf1rrXZjVK4dgYF4YoYcSge79djW7BeTgZvqDB3u KrWQUYext6NRYqvXZsLLOFZsQUnhTI209D7wHsRVmWUxp7atqv29M/0lqYsGCNHHGuq2 HxgQ== X-Gm-Message-State: ALoCoQl72ddoys0BZNyz49T/GDIrNJuJ0QhVTKHHzH0YVPZ2sA/1+lwr963yREcuotPtvG0xk4xL X-Received: by 10.68.232.132 with SMTP id to4mr76811pbc.141.1383517702466; Sun, 03 Nov 2013 14:28:22 -0800 (PST) Received: from [10.0.1.4] (dy4.sdf.com. [216.113.193.88]) by mx.google.com with ESMTPSA id ka3sm24131222pbc.32.2013.11.03.14.28.20 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 03 Nov 2013 14:28:21 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.0 \(1816\)) Subject: Re: HDD-manufacture induced ZFS limitations From: Tom Samplonius In-Reply-To: Date: Sun, 3 Nov 2013 14:28:18 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: <7808D09C-D497-480B-AB88-FA300485B3CE@samplonius.org> References: To: Zenny X-Mailer: Apple Mail (2.1816) Cc: freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 03 Nov 2013 23:30:57 -0000 On Nov 3, 2013, at 1:07 AM, Zenny wrote: > Hi: >=20 > PROBLEM >=20 > I came across a very weird situation because HDD-manufacturer counts > HDD space according to metric system instead of multiplication of 1024 That is not weird or unusual. For example, 72GB disks range from 72GB = to 73.1GB (or so) in size. It doesn't really have anything to do with = the 1024 vs 1000 measurement issue. Manufacturing variations result in = a lot of different sizes. Major commercial storage vendors automatically round down to the = nearest known increment. This worked well for SCSI disks, as they = always doubled in size each generation (9, 18, 36, 72, 144, etc.). It = doesn't work as well with SATA disks. Or down to the nearest whole GB, if it is not a known size. Tom=