From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760950AbZEMROR (ORCPT ); Wed, 13 May 2009 13:14:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759904AbZEMRN7 (ORCPT ); Wed, 13 May 2009 13:13:59 -0400 Received: from wf-out-1314.google.com ([209.85.200.174]:47656 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759162AbZEMRN6 (ORCPT ); Wed, 13 May 2009 13:13:58 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type :content-transfer-encoding; b=pHshilKWfP+lPUr/p1Eth5ADya4VoYQm4705rWgPrTfEgPjHel1N6W/bm0/k/no/sl RvUpStrmXlLTjYjxj5sznllQtiPrMQ3iLinOTVXJQIAn7F9WYe00D45HX63l8XmJ4TG/ TK1jtdfX3banWnur0oUcyrMNcIBmLzXdK5Ubs= MIME-Version: 1.0 Date: Wed, 13 May 2009 13:13:58 -0400 Message-ID: Subject: filesystem with integrity checking From: crimil tradalo To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I am looking for a filesystem that supports integrity checking of files with some kind of checksum/hash. For example, for each block an SHA hash is stored when written and verified when read. If the underlying hardware has corrupted the data, or returned a different block than expected, the filesystem can detect the error. Obviously, ideal would be integration with the RAID layer so that valid data could be found in the redundancy, similar to ZFS, but I don't expect this to exist. The last time I saw this discussed, the consensus seemed to be that it wasn't worth the CPU time. I hope that as CPUs have gotten faster and data sets larger, more people are noticing how frequent data corruption occurs and are beginning to respect the value of an OS ensuring the integrity of data on permanent storage. Everyone here must have experienced data corruption that is either seemingly-random or traced to bad hardware. I'd like to detect such corruption as soon as it happens, rather than after it has caused a catastrophic loss of data. If there is none that currently supports this, I am curious if any intend to support it eventually. I see it mentioned in BTRFS documentation, but considering the low odds of a new filesystem actually becoming viable, I'm more interested in a practical solution. My understanding is that the only filesystems that offer this are ZFS and WAFL, neither of which is going to be useful on Linux of course.