From owner-freebsd-arm@freebsd.org Tue Mar 22 04:39:38 2016 Return-Path: Delivered-To: freebsd-arm@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 CCF38AD69B9 for ; Tue, 22 Mar 2016 04:39:38 +0000 (UTC) (envelope-from russ.haley@gmail.com) Received: from mail-vk0-x231.google.com (mail-vk0-x231.google.com [IPv6:2607:f8b0:400c:c05::231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 867B97E2 for ; Tue, 22 Mar 2016 04:39:38 +0000 (UTC) (envelope-from russ.haley@gmail.com) Received: by mail-vk0-x231.google.com with SMTP id k1so240150433vkb.0 for ; Mon, 21 Mar 2016 21:39:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc; bh=3FhTsMCBaf1e1QL+Q+Z2tIFEfjF+YHmU0PMH8jZvCJw=; b=P8tnYBlsLI50W+6AEgHS5AU/pdELvMp1ObYKuIQeHeMyr2kee56bkiCA+LQuKHDFmx 0hNAfFbwxKnSfsrBeW0WGpVWWPr4n+mNK2+ceEj6p2O5pes8N1RNjocxIlmqMB0Is0L/ JCd9Lj6swNI2epb8jhQHxp6/C9Rg2YAWtBmg8ScVb6PomZltiylw5s5awNjDJZuTbf0n tZv3bY8Fj46P0amB1XYQEw8UYQ3swDDYpvmTaY2cHyhIMnBQ/8Jbi7A+I2QPrPnhea2j FzkoCdVJyK9vY8rf715uUK4QApT0rBf5/SPLomeQskLbxwJwjB/dHJxR17DepEZtlEfa iV3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc; bh=3FhTsMCBaf1e1QL+Q+Z2tIFEfjF+YHmU0PMH8jZvCJw=; b=V2pLyxrXGnPmtoE2rw7YCkUmCYDCZWx66RLVE5FitriXNErzhsAPYDhHXee5nuRPjT rXLDZUUybzexreJASfisjFEvnl1j8P0qn5bimPSJMhv5lY1fuiZUIZgP6Cv7/4ecMj/W vgGIXYu2UDXB3LJKRgxPm/RPov+LG8laKkW+MX4bxEvoKrGvewkyCAN/K+pCETkQie6Y 3p56LrbHKLL1ws8AXDeIhQsa9V7rdbIDNyMAF9Mbrakgx9jeV+XNRc9n0jN1XDp8qvB6 c3lIZlRi+LO3yLc22kMNerXViX1dLHGcOBtyjIvlbqiHCS++GG0NjvtZkNwODcByj2J6 R4Xw== X-Gm-Message-State: AD7BkJJepEfn9cYSuIEZ/pGsAw4e5Um81B9B5/c/26CixR9jyOQi1n2g011gWU7Q6J/K0Mx+Lubp6jRmT6WuAA== MIME-Version: 1.0 X-Received: by 10.31.45.143 with SMTP id t137mr33267372vkt.143.1458621577747; Mon, 21 Mar 2016 21:39:37 -0700 (PDT) Received: by 10.31.54.13 with HTTP; Mon, 21 Mar 2016 21:39:37 -0700 (PDT) In-Reply-To: <271EF73A-077C-44A5-8B58-721405800B9F@bsdimp.com> References: <20160321175952.GA83908@www.zefox.net> <1458586884.68920.96.camel@freebsd.org> <20160321221153.GB83908@www.zefox.net> <1458600070.68920.107.camel@freebsd.org> <1973487B-0AA7-468D-A9CC-319FBE2122F0@netgate.com> <20160322033417.GD83908@www.zefox.net> <271EF73A-077C-44A5-8B58-721405800B9F@bsdimp.com> Date: Mon, 21 Mar 2016 21:39:37 -0700 Message-ID: Subject: Re: Effect of partitioning on wear-leveling From: Russell Haley To: Warner Losh Cc: bob prohaska , freebsd-arm Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Mar 2016 04:39:38 -0000 How long can nand go without power before it starts to lose data integrity? Thanks, Russ On Mon, Mar 21, 2016 at 8:48 PM, Warner Losh wrote: > >> On Mar 21, 2016, at 9:34 PM, bob prohaska wrote: >> >> On Mon, Mar 21, 2016 at 08:38:13PM -0600, Warner Losh wrote: >>> >>> One thing that people forget is that the underlying blocks that are written >>> are completely independent of what lba is used to write it. So the notion >>> that you have blocks normally part of /var or /tmp no longer makes sense. >>> Between writing blocks in different order and garbage collection, modern SD >>> cards do a good job of wear averaging. How much you've written to the drive >>> in total drives wear out these days. >>> >> >> How do modern flash devices report end of life? Do problems show up in error >> logs, or does the device simply refuse to work with no warning? > > Undefined. Either it goes read-only or read-never. :) > > Warner >