From owner-freebsd-questions@freebsd.org Fri Mar 17 09:05:07 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 47F72D10649 for ; Fri, 17 Mar 2017 09:05:07 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mailrelay14.qsc.de (mailrelay14.qsc.de [212.99.163.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.antispameurope.com", Issuer "TeleSec ServerPass DE-2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 9866D17A8 for ; Fri, 17 Mar 2017 09:05:05 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mx01.qsc.de ([213.148.129.14]) by mailrelay14.qsc.de; Fri, 17 Mar 2017 10:04:09 +0100 Received: from r56.edvax.de (port-92-195-127-117.dynamic.qsc.de [92.195.127.117]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx01.qsc.de (Postfix) with ESMTPS id E54D83D063; Fri, 17 Mar 2017 10:04:06 +0100 (CET) Received: from r56.edvax.de (localhost [127.0.0.1]) by r56.edvax.de (8.14.5/8.14.5) with SMTP id v2H946rI001962; Fri, 17 Mar 2017 10:04:06 +0100 (CET) (envelope-from freebsd@edvax.de) Date: Fri, 17 Mar 2017 10:04:06 +0100 From: Polytropon To: Ralf Mardorf Cc: Ralf Mardorf via freebsd-questions Subject: Re: bootable ext. USB SSD for backup Message-Id: <20170317100406.b8e3d390.freebsd@edvax.de> In-Reply-To: <20170316213722.139560c8@archlinux.localdomain> 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> Reply-To: Polytropon Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-cloud-security-sender: freebsd@edvax.de X-cloud-security-recipient: freebsd-questions@freebsd.org X-cloud-security-Virusscan: CLEAN X-cloud-security-disclaimer: This E-Mail was scanned by E-Mailservice on mailrelay14.qsc.de with 5B4F368342E X-cloud-security-connect: mx01.qsc.de[213.148.129.14], TLS=1, IP=213.148.129.14 X-cloud-security: scantime:.5616 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: Fri, 17 Mar 2017 09:05:07 -0000 On Thu, 16 Mar 2017 21:37:22 +0100, 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. Few years ago, I read that SSDs that are sold with size n are actually produced as size 2 * n due to high failure rate during production... The 1000 vs. 1024 factor problem aside, it might also be that marketing TB are calculated with "Windows" file system overhead in mind (actually usable for user files vs. occupied disk space with FS data, metadata, directories, and actual files). > 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 ;). It's a _magical_ disk where data loss leads to more usable disk space for user files. ;-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...