From owner-freebsd-fs@FreeBSD.ORG Fri Mar 2 16:28:55 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 990B11065676 for ; Fri, 2 Mar 2012 16:28:55 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-vx0-f182.google.com (mail-vx0-f182.google.com [209.85.220.182]) by mx1.freebsd.org (Postfix) with ESMTP id 45E668FC26 for ; Fri, 2 Mar 2012 16:28:50 +0000 (UTC) Received: by vcmm1 with SMTP id m1so385701vcm.13 for ; Fri, 02 Mar 2012 08:28:50 -0800 (PST) Received-SPF: pass (google.com: domain of fjwcash@gmail.com designates 10.52.36.176 as permitted sender) client-ip=10.52.36.176; Authentication-Results: mr.google.com; spf=pass (google.com: domain of fjwcash@gmail.com designates 10.52.36.176 as permitted sender) smtp.mail=fjwcash@gmail.com; dkim=pass header.i=fjwcash@gmail.com Received: from mr.google.com ([10.52.36.176]) by 10.52.36.176 with SMTP id r16mr16925106vdj.84.1330705730456 (num_hops = 1); Fri, 02 Mar 2012 08:28:50 -0800 (PST) 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:content-type:content-transfer-encoding; bh=lugs2pe76pPqrx1l8hsLGhXzZ34A0XqEB16u+Z/NSqQ=; b=Y3ZlI3Z6Puq3S2M7SR7U7dzBZo7NWGDNxAoVCxiRBBwhL0F6qQ2ezwwfbHkDl1cqkq kjqjNKBtVSMaMzedDeBRgdXxTa0yn6sdxSPIk5GEobCn11e21CNLIybcs7dgSlNWEG1F Rl0+r9CLL2lDWCbt+KyoBEcxlFuxqqvzuiGQNhlHsVqe4fRJsV9poBMo3oFn/ZCHBT7O 0JYAyulGgjIrQ6K7mrqyRiz4ymxYYziBW6dD/Al35ckwVs02NGSXibvkfPucG+PJqZ+d l0S/YCRzafIRbh9XnLHm4xJFPGQnTm/UVvZvN/1NQY7Hhb5HI56U2ydjZ1zM0uyk+ecb Gdsg== MIME-Version: 1.0 Received: by 10.52.36.176 with SMTP id r16mr14363276vdj.84.1330705730372; Fri, 02 Mar 2012 08:28:50 -0800 (PST) Received: by 10.220.178.74 with HTTP; Fri, 2 Mar 2012 08:28:50 -0800 (PST) In-Reply-To: <201203021530.q22FUjOU040478@fire.js.berklix.net> References: <4F4FC3E1.5040700@freebsdfoundation.org> <201203021530.q22FUjOU040478@fire.js.berklix.net> Date: Fri, 2 Mar 2012 08:28:50 -0800 Message-ID: From: Freddie Cash To: "Julian H. Stacey" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org, Deb Goodkin Subject: Re: [FreeBSD-Announce] Foundation Announces NAND File System for FreeBSD Project X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Mar 2012 16:28:55 -0000 On Fri, Mar 2, 2012 at 7:30 AM, Julian H. Stacey wrote: > Hi freebsd-fs@freebsd.org > cc Deb > > Deb Goodkin wrote to announce@ Thu, 01 Mar 2012 11:45:53 -0700 (19:45 CET= ): >> The FreeBSD Foundation is pleased to announce that Semihalf, an > ... > > I was interested to read more background, but no URLs, > so I found http://www.semihalf.com/ & re. > =C2=A0 =C2=A0 =C2=A0 =C2=A0NAND Flash File System > found: > =C2=A0http://en.wikipedia.org/wiki/Flash_memory#NAND_flash > =C2=A0 =C2=A0 =C2=A0 =C2=A0"Manufacturers try to maximize the amount of u= sable storage > =C2=A0 =C2=A0 =C2=A0 =C2=A0by shrinking the size of the transistor below = the size where > =C2=A0 =C2=A0 =C2=A0 =C2=A0they can be made reliably, to the size where f= urther > =C2=A0 =C2=A0 =C2=A0 =C2=A0reductions would increase the number of faults= faster than > =C2=A0 =C2=A0 =C2=A0 =C2=A0it would increase the total storage available.= " > =C2=A0 =C2=A0 =C2=A0 =C2=A0- > =C2=A0 Really scarey if that is taken literaly, I jhs@ presume loose phra= seology, > =C2=A0 =C2=A0 =C2=A0 =C2=A0hopefully someone who knows more will rephrase= that :-). A good primer on NAND Flash with lots of info on "the next hot thing", triple-level cell (TLC) flash, which has all the flaws of MLC multiplied many times over, but is a lot less expensive to use/make, so expect it to hit consumer drives this year. :( Page 3 is extremely enlightening about the issues, especially regarding the increased CRC requirements in order to actually read a valid bit from the cell. --=20 Freddie Cash fjwcash@gmail.com