From owner-freebsd-questions@freebsd.org Thu Mar 16 20:47:44 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E4C45D0F99B for ; Thu, 16 Mar 2017 20:47:44 +0000 (UTC) (envelope-from ephaeton@gmx.net) Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3F7941D5C for ; Thu, 16 Mar 2017 20:47:43 +0000 (UTC) (envelope-from ephaeton@gmx.net) Received: from [10.0.0.2] ([194.118.106.252]) by mail.gmx.com (mrgmx002 [212.227.17.190]) with ESMTPSA (Nemesis) id 0Lg0sd-1cPwjM3hLH-00pah7 for ; Thu, 16 Mar 2017 21:47:36 +0100 Subject: Re: bootable ext. USB SSD for backup To: freebsd-questions@freebsd.org References: <20170316194612.GA1748@c720-r314251> <33953.128.135.52.6.1489694167.squirrel@cosmo.uchicago.edu> <92024f3c-2ab3-1741-97de-36455ca56b7e@gmx.net> <20170316213722.139560c8@archlinux.localdomain> From: "Martin S. Weber" Message-ID: <3c607797-bdae-992e-2783-bb066b15e86d@gmx.net> Date: Thu, 16 Mar 2017 21:47:33 +0100 User-Agent: Mozilla/5.0 (X11; Linux armv7l; rv:45.0) Gecko/20100101 Icedove/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170316213722.139560c8@archlinux.localdomain> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:hme4DJj8IGLrcbPAr3gP99yVN75RWaWHkRWTq+idYqAZ2g9rLyb 185zujZq1ALK1Q717b8UcxaP1A3BvJDKI4hD+2jpOwZ1M8V9+p1n5EQ/PP4A9tEiL+mWk/0 aiP93iXEpdFlb/PHHc0Wb7oGuuxr4QiO3LiXpuxDD1m0vEjXpRDwNn+vEDoX+Jf40icJgd0 HOsf95hAxMkueu7LXfyAw== X-UI-Out-Filterresults: notjunk:1;V01:K0:3jETJH8BuYE=:T1qAAd8/DCekB9b9p80NVN wn1tKoV2iywBKK4Tl8moO8jy23eU3ivA4tPP0YYKfmdF0adEj8wQd5c0dv3Rb9qE5fT9lCj9E U6gQLf7rO2Y9rBIqEtRfXxjz9v7DOyib56zAxWOlWc7JoIOkgDRSnjLbOmzNyfVp6bstwIhY4 MmmPmLgWmwmwOVkj9+05dKfHxZ3tASweCSarmyRB695olbMdlxCm9cOOzL1jmaDbIby2/JDGY zUo+ReCm6Rt/s58svdwd4dvJIFSaZfTFJrqQTTx7xY+yxlQGqRZBuU/0zwb18XnrECxKvljzj mAAp847v8cUHJIudNxtbbOE73U3ZiAYoG1xqYT5BEE8+qDrKSW/P226ADXqd7mrKo9gQAMweq /CqzvrVCMH2rV3RrQ2WW8Wsp4+9yHnHGjYOFChB9TK31NF3ORc6UhYA/g8xthLIYQ9XoU8Z0k job5WtbfT6yLDIMqkJWLyYtpUlav9yciil3cjTnEfPoM5mra40dqCTJszd1TxJ5OztkhxX+iz 2byup/UyDKjAiQXLKImBVBVzODsrpITyirr4O8GQaw8BCXnpgL4AO9jy/AkxQznjRSOiN5vQa BsCvhRv9gM7Fd/JwNHT8xunmn/IPcucNRkmMicJOBq+J0b9o5TlyDeY9gylKd3svkg22LE61j o+bApou4UkGkaTamyhympmvYBikSosCzwQFkctFL+qkwMeRPg5IUFCULH1eYTDLJ6kz/J9IEX U6svPUrZXc7dZ5j1PF4nLhnoRROu/UkGGC6VXSzRWI1KGFxdN7aO78HPVFeVtU4D7x6QyDyob nwXld7L X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Mar 2017 20:47:45 -0000 On 03/16/17 21:37, Ralf Mardorf via freebsd-questions wrote: > On Thu, 16 Mar 2017 21:11:53 +0100, Martin S. Weber wrote: >> Toshiba is clearly underselling the disk. > > I don't think so, I suspect that some bytes are reserved to compensate > borked memory locations. > > [rocketmouse@archlinux ~]$ sudo smartctl -a /dev/sda | head -9 > smartctl 6.5 2016-05-07 r4318 > [x86_64-linux-4.9.13-rt12-1-rt-persianrug] (local build) Copyright (C) > 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org > > === START OF INFORMATION SECTION === > Device Model: TOSHIBA-TL100 > Serial Number: Y69B703NKKEU > LU WWN Device Id: 5 00080d c0061b7c8 > Firmware Version: SBFZ10.3 > User Capacity: 240,057,409,536 bytes [240 GB] > > GParted mentions 223.57 GiB * 1024 * 1024 = 234,430,136.32 bytes. > MBR, file system entries might take some space, too. OTOH the complete > capacity shouldn't shrink ;). bc is your friend: 223.57*2^30 (actually GiB, not 1024*1024 which is MiB) 240056459591.68 and compare to your 240057409536 from above. The difference is slightly less than a MiB: scale=3 (240057409536 - 223.57*2^30)/2^20 .905 Can we stop this excursion now? AFAIK the extra bytes which are to be used as reserve aren't actually reported by the drive. Regards