From owner-freebsd-questions@freebsd.org Sun Feb 24 14:34:51 2019 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B443E1520B6B for ; Sun, 24 Feb 2019 14:34:51 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from kicp.uchicago.edu (kicp.uchicago.edu [128.135.20.70]) by mx1.freebsd.org (Postfix) with ESMTP id DB8BD6F7E3 for ; Sun, 24 Feb 2019 14:34:50 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from [10.0.0.8] (adsl-108-68-160-152.dsl.chcgil.sbcglobal.net [108.68.160.152]) by kicp.uchicago.edu (Postfix) with ESMTP id D878D718047 for ; Sun, 24 Feb 2019 08:34:49 -0600 (CST) Subject: Re: Recover failed SD card To: freebsd-questions@freebsd.org References: <2341a9ac-42aa-737e-441f-b69cccc826c6@netfence.it> <1D49330E-F047-4F86-8F37-A54980624332@kreme.com> From: Valeri Galtsev Message-ID: <16fe9803-9978-df84-7534-d46803e8e08d@kicp.uchicago.edu> Date: Sun, 24 Feb 2019 08:34:49 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <1D49330E-F047-4F86-8F37-A54980624332@kreme.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: DB8BD6F7E3 X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dmarc=fail reason="" header.from=uchicago.edu (policy=none) X-Spamd-Result: default: False [0.50 / 15.00]; ARC_NA(0.00)[]; DMARC_POLICY_SOFTFAIL(0.10)[uchicago.edu : No valid SPF, No valid DKIM,none]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-0.75)[-0.753,0]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; TO_DN_NONE(0.00)[]; NEURAL_SPAM_MEDIUM(0.38)[0.379,0]; RCPT_COUNT_ONE(0.00)[1]; IP_SCORE(-0.01)[country: US(-0.07)]; NEURAL_SPAM_SHORT(0.79)[0.794,0]; MX_GOOD(-0.01)[cached: kicp.uchicago.edu]; RCVD_IN_DNSWL_NONE(0.00)[70.20.135.128.list.dnswl.org : 127.0.10.0]; R_SPF_NA(0.00)[]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:160, ipnet:128.135.0.0/16, country:US]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 24 Feb 2019 14:34:52 -0000 On 2/23/19 6:46 PM, @lbutlr wrote: > On 23 Feb 2019, at 13:50, Bruce Ferrell wrote: >> Unfortunately flash memory "wears out". There are spare storage blocks and logic to level wear by switching th the spares when main block failures are detected. > > Yeah, that’s good theory, but it’s not what has happened with mine. Genrally they fail in the first few weeks. Even if it takes longer, it is not like they have been written and rewritten many times. This isn’t a wear issue, it is an "SD Cards Break easily" issue. > With all statements like that I would really like to hear at least the following about failed devices: 1. brand and model of device that failed on you 2. the source (vendor) you got the device from The truth is that there is lot of garbage that is manufactured and sold, and flash cards are the ones that have really gross difference between good (proper) ones and bad ones. Finite number of write operations is in specifications od flash memory. Fatal failure after short use is not, and is an indication of garbage device. Another example in the same lines would be rechargeable batteries (specifically: 16340 LiPo were the ones I was getting for myself recently, and it took me quite some effort to pick the good ones - knocking on wood). Now, I use and used in my car camera (read: written and overwritten all the time I drive), no failures: 1. High grade Samsung 128GB 100MB/s (U3) MicroSD EVO Select; 2. This one I do not consider the best, but it survived at least 6 years of use in car camera: Micro Center class 10 Micro SD (32 GB) So, instead of generalizing, I would really like to hear the detailed information about _failed_ devises Just my $0.02 Valeri -- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++