From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:33606 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750989AbaHXA5A (ORCPT ); Sat, 23 Aug 2014 20:57:00 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XLM79-0003eo-5z for linux-btrfs@vger.kernel.org; Sun, 24 Aug 2014 02:56:59 +0200 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 24 Aug 2014 02:56:59 +0200 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 24 Aug 2014 02:56:59 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: superblock checksum mismatch after crash, cannot mount Date: Sun, 24 Aug 2014 00:56:47 +0000 (UTC) Message-ID: References: <53F7BD8E.10308@floga.de> <53F85317.8060900@floga.de> <20140823163803.GA9149@hungrycats.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Zygo Blaxell posted on Sat, 23 Aug 2014 12:38:05 -0400 as excerpted: > Consumer SD cards are /terrible/ storage devices. Always back up all > data written to an SD card as soon as possible after writing it, and > develop a process to restore the backup to a new SD card conveniently > when--not if--the card fails. > > Over the years I've burned my way through dozens of SD cards in Pis, > Beagles, x86 laptops, USB SD card readers, cameras and cell phones. > I have more bad or failed cards than good ones in my collection, but no > more than three of any specific model. Brand, price, and specs don't > correlate to success or failure. Even the good cards wear out after > heavy use. The bad ones fail much faster, and are more likely to give > you garbage data instead of properly formed I/O errors as they fail. I had read that it was bad, but I didn't know it was /that/ bad. The ones I've used have tended to be write-once, read for quite some time, often lose (or throw away as obsolete due to tiny size) before I write them again, or at least before I write them half a dozen times, and I've generally not has problems with them doing that, but I wouldn't tend to know about routine rewrite behavior. Sounds like it's much worse than I might have thought. Thanks. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman