Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261550AbVEYUeJ (ORCPT ); Wed, 25 May 2005 16:34:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261551AbVEYUeJ (ORCPT ); Wed, 25 May 2005 16:34:09 -0400 Received: from 1-1-4-20a.ras.sth.bostream.se ([82.182.72.90]:48792 "EHLO garbo.kenjo.org") by vger.kernel.org with ESMTP id S261550AbVEYUeD (ORCPT ); Wed, 25 May 2005 16:34:03 -0400 Subject: Re: NFS corruption on 2.6.11.7 From: Kenneth Johansson To: "David S.Miller" Cc: trond.myklebust@fys.uio.no, linux-kernel@vger.kernel.org In-Reply-To: <20050525.131616.59655785.davem@davemloft.net> References: <1116929711.6237.8.camel@tiger> <1116936088.10707.39.camel@lade.trondhjem.org> <1117052007.9884.10.camel@tiger> <20050525.131616.59655785.davem@davemloft.net> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-7wzjPmMhINxi3v1e0EsM" Date: Wed, 25 May 2005 22:34:01 +0200 Message-Id: <1117053241.9884.18.camel@tiger> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1850 Lines: 53 --=-7wzjPmMhINxi3v1e0EsM Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2005-05-25 at 13:16 -0700, David S.Miller wrote: > From: Kenneth Johansson > Date: Wed, 25 May 2005 22:13:27 +0200 >=20 > > Is there some fundamental difference in how nfs over upd and tcp is > > handled regarding the packet contents like tcp using the tcp checksum > > and udp not using the udp checksum or something like that? > >=20 > > Are there any counters for checksum errors in udp and tcp that can be > > read ?? I faild to spot anything in /proc. >=20 > If you are on a gigabit or faster network, IPv4 fragment sequence > numbers can wrap and if you are very unlucky the checksums will > match as well corrupting your data. This is a fatal limitation of > the small 16-bit IPv4 framgent ID. >=20 > Use TCP for NFS unless you want NFS data corruption. >=20 Unlikely to be the case this time. I get a sequence of 28 bytes that is wrong in the data and often the wrong data is a copy from data 64 or 128 byte earlier in the file. If this was not on a PC with cache coherency I would guess that someone forgot to do a cache invalidate/flush. But I do wonder why I only see this problem with nfs over udp.=20 --=-7wzjPmMhINxi3v1e0EsM Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBClOE4mDGOmJIy9x8RAjBtAJwPJyP0b9Qvd9R/iFJplU0yZMZd+ACfeEAk POokAzyzB1Xdwa4WjeMoVZE= =nQLg -----END PGP SIGNATURE----- --=-7wzjPmMhINxi3v1e0EsM-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/