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Date: Tue, 31 Jan 2012 11:28:26 -0800
Message-ID: <CAF3hT9AgVpcZkGLkr4EH4x4heNFgxNykM4Mp3V_C-RBSwJh7mA@mail.gmail.com>
Subject: Re: [LSF/MM TOPIC] end-to-end data and metadata corruption detection
From: Gregory Farnum <gregory.farnum@dreamhost.com>
To: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        lsf-pc@lists.linux-foundation.org,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        linux-scsi@vger.kernel.org,
        Sven Breuner <sven.breuner@itwm.fraunhofer.de>
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Sender: linux-nfs-owner@vger.kernel.org

On Tue, Jan 31, 2012 at 11:22 AM, Bernd Schubert
<bernd.schubert@itwm.fraunhofer.de> wrote:
> I guess we should talk to developers of other parallel file systems and see
> what they think about it. I think cephfs already uses data integrity
> provided by btrfs, although I'm not entirely sure and need to check the
> code. As I said before, Lustre does network checksums already and *might* be
> interested.

Actually, right now Ceph doesn't check btrfs' data integrity
information, but since Ceph doesn't have any data-at-rest integrity
verification it relies on btrfs if you want that. Integrating
integrity verification throughout the system is on our long-term to-do
list.
We too will be said if using a kernel-level integrity system requires
using DIO, although we could probably work out a way to do
"translation" between our own integrity checksums and the
btrfs-generated ones if we have to (thanks to replication).
-Greg