From owner-freebsd-geom@FreeBSD.ORG Mon Aug 13 17:33:27 2007 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8322316A420 for ; Mon, 13 Aug 2007 17:33:27 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (arm132.internetdsl.tpnet.pl [83.17.198.132]) by mx1.freebsd.org (Postfix) with ESMTP id E8D1313C45B for ; Mon, 13 Aug 2007 17:33:26 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 4DFDF487F8; Mon, 13 Aug 2007 19:15:21 +0200 (CEST) Received: from localhost (public-gprs36066.centertel.pl [91.94.12.252]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id E8A0E45CD9; Mon, 13 Aug 2007 19:15:06 +0200 (CEST) Date: Mon, 13 Aug 2007 19:14:01 +0200 From: Pawel Jakub Dawidek To: Ivan Voras Message-ID: <20070813171401.GA8819@garage.freebsd.pl> References: <31903.4141.qm@web30306.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ew6BAiZeqk4r7MaW" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 7.0-CURRENT i386 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=BAYES_00,RCVD_IN_NJABL_DUL autolearn=no version=3.0.4 Cc: freebsd-geom@freebsd.org Subject: Re: Gvirstor "newfs" problem - help needed X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Aug 2007 17:33:27 -0000 --ew6BAiZeqk4r7MaW Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 13, 2007 at 02:12:50PM +0200, Ivan Voras wrote: > Arne W=F6rner wrote: > > Hi! > >=20 > > --- Ivan Voras wrote: > >> cg 0: bad magic number > >> > > I know that message from my tests with graid5... > > It was clearly caused by a bug in graid5, but I cannot remember when or= why it > > happened... > > I would guess, it happened because of some cache or request-sorting > > mismanagement (the write didnt take place but the read was executed; or= the > > second write took place before the first write)... Is that possible in > > gvirstor? Does newfs create such a request-pattern (overlapping write r= equests > > <-- would be a little bit astonishing)? > >=20 > > But I can definitely say, that it was a bug in graid5... >=20 > Thanks for replying! gvirstor doesn't reorder IO and i doesn't have a > cache, so it's not that. I agree that it's almost certainly a bug in > gvirstor. >=20 > The only "slightly unusual" thing newfs does is that it first writes a > "big" block, then reads a smaller block from within the written big > block and doesn't like what it gets. But this scenario is well tested by > my test cases and I don't see why it fails for newfs. Ivan, try to configure gvirstor on top of gnop. Modify gnop to log only requests between 81920 and 147456 (81920 + 65536). Something like: if ((bp->bio_offset >=3D 81920 && bp->bio_offset < 147456) || (bp->bio_offset + bp->bio_length >=3D 81920 && bp->bio_offset + bp->bio_length < 147456)) { G_NOP_LOGREQ(bp, "Request."); } Run newfs and watch which gvirstor I/O request triggers request into this area - my guess is that gvirstor recalculates something incorrectly and instead of writting somewhere else it writes into this very place. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --ew6BAiZeqk4r7MaW Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFGwJFZForvXbEpPzQRAuKdAKCP+6v6rVdVfA21jRIwoth2QYEUEgCg1O7K lo7h3RwFK10hHsKTTMlkrN8= =NSgv -----END PGP SIGNATURE----- --ew6BAiZeqk4r7MaW--