From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Greg Freemyer" Subject: Data Recovery from SSDs - Impact of trim? Date: Fri, 9 Jan 2009 17:27:16 -0500 Message-ID: <87f94c370901091427n74fc8d9apa569c44df12dc099@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from qw-out-2122.google.com ([74.125.92.26]:53811 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759468AbZAIW1S (ORCPT ); Fri, 9 Jan 2009 17:27:18 -0500 Received: by qw-out-2122.google.com with SMTP id 3so8708893qwe.37 for ; Fri, 09 Jan 2009 14:27:16 -0800 (PST) Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Dongjun Shin , IDE/ATA development list Dongjun (with linux-ide in copy), I got your name from a Linux Kernel posting and I was wondering if you could help me understand if data recovery will be possible with SSDs in the future. I work a lot with data recovery and forensic imaging. With both, access to what the filesystem considers unallocated sectors / blocks / clusters is key to the process. ie. A user deletes a file, but needs to restore it. Lots of recovery tools exist to assist in this, but obviously they need to be able to read the no longer allocated clusters. With a DISCARD enabled filesystem / kernel and with both current and future generation SSDs, I'm curious if our tools are going to be able to read this information anymore. Per the proposed spec Tejun posted a link to a couple months ago, the response to a ATA read request of a trimmed sector can either be the original data or all zeros. http://t13.org/Documents/UploadedDocuments/docs2007/e07154r3-Data_Set_Management_Proposal_for_ATA-ACS2.pdf >>From my industries perspective we would very much like the original data to be returned as long as it is available. Can you provide any insight into how the manufacturers are planning to implement such reads? Thanks Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com