From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:55880 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751895AbdDRDX3 (ORCPT ); Mon, 17 Apr 2017 23:23:29 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1d0Jje-0002dh-0Y for linux-btrfs@vger.kernel.org; Tue, 18 Apr 2017 05:23:22 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: Btrfs/SSD Date: Tue, 18 Apr 2017 03:23:13 +0000 (UTC) Message-ID: References: <8f046fa5-a458-9db8-b616-907afd34383b@gmail.com> <20170417232419.04474015@natsu> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Roman Mamedov posted on Mon, 17 Apr 2017 23:24:19 +0500 as excerpted: > Days are long gone since the end user had to ever think about device > lifetimes with SSDs. Refer to endurance studies such as > http://techreport.com/review/27909/the-ssd-endurance-experiment-theyre- all-dead > http://ssdendurancetest.com/ > https://3dnews.ru/938764/ > It has been demonstrated that all SSDs on the market tend to overshoot > even their rated TBW by several times, as a result it will take any user > literally dozens of years to wear out the flash no matter which > filesystem or what settings used Without reading the links... Are you /sure/ it's /all/ ssds currently on the market? Or are you thinking narrowly, those actually sold as ssds? Because all I've read (and I admit I may not actually be current, but...) on for instance sd cards, certainly ssds by definition, says they're still very write-cycle sensitive -- very simple FTL with little FTL wear- leveling. And AFAIK, USB thumb drives tend to be in the middle, moderately complex FTL with some, somewhat simplistic, wear-leveling. While the stuff actually marketed as SSDs, generally SATA or direct PCIE/ NVME connected, may indeed match your argument, no real end-user concern necessary any more as the FTLs are advanced enough that user or filesystem level write-cycle concerns simply aren't necessary these days. So does that claim that write-cycle concerns simply don't apply to modern ssds, also apply to common thumb drives and sd cards? Because these are certainly ssds both technically and by btrfs standards. -- 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