From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id n1P6fnFN191491 for ; Wed, 25 Feb 2009 00:41:50 -0600 Received: from mailsrv1.zmi.at (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 8635F150F92 for ; Tue, 24 Feb 2009 22:41:17 -0800 (PST) Received: from mailsrv1.zmi.at (mailsrv1.zmi.at [212.69.162.198]) by cuda.sgi.com with ESMTP id vpSfXcqeQHXJbzE8 for ; Tue, 24 Feb 2009 22:41:17 -0800 (PST) Received: from mailsrv2.i.zmi.at (h081217054243.dyn.cm.kabsi.at [81.217.54.243]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client CN "mailsrv2.i.zmi.at", Issuer "power4u.zmi.at" (not verified)) by mailsrv1.zmi.at (Postfix) with ESMTP id CBD8E42B5 for ; Wed, 25 Feb 2009 07:40:43 +0100 (CET) Received: from saturn.localnet (saturn.i.zmi.at [10.0.0.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mailsrv2.i.zmi.at (Postfix) with ESMTPSA id D7266400174 for ; Wed, 25 Feb 2009 07:40:43 +0100 (CET) From: Michael Monnerie Subject: Re: XFS and XEN Date: Wed, 25 Feb 2009 07:40:33 +0100 References: <200902170959.55077@zmi.at> <200902241604.29566@zmi.at> <20090224163823.GA19811@infradead.org> In-Reply-To: <20090224163823.GA19811@infradead.org> MIME-Version: 1.0 Message-Id: <200902250740.43223@zmi.at> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============6330066388149676925==" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com --===============6330066388149676925== Content-Type: multipart/signed; boundary="nextPart3296521.54puIVQzs9"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit --nextPart3296521.54puIVQzs9 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Dienstag 24 Februar 2009 Christoph Hellwig wrote: > It's the usual BS. =A0The difference is just that you actually see the > corruption on XFS while it's pretty silent on extN. =A0If your Hardware > (or Hypervisor) is not reliable you _will_ lose data. =A0Either > silently or with a spectacular blowup if the filesystem actually has > consistency checking (which XFS has a lot). Thank you for the explanation. So to clear up: It was not XFS's fault,=20 but came from XEN? Can I write it like that on the FAQ?: Q: Which settings are best with virtualization like VMware, XEN, qemu? The biggest problem is that those products seem to also virtualize disk=20 writes in a way that even barriers don't work anymore, which means even=20 a fsync is not reliable. Tests confirm that unplugging the power from=20 such a system even with RAID controller with battery backed cache and=20 hard disk cache turned off (which is save on a normal host) you can=20 destroy a database within the virtual machine (client, domU whatever you=20 call it). In qemu you can specify cache=3Doff on the line specifying the virtual=20 disk. For others I have no information what to do. mfg zmi =2D-=20 // Michael Monnerie, Ing.BSc ----- http://it-management.at // Tel: 0660 / 415 65 31 .network.your.ideas. // PGP Key: "curl -s http://zmi.at/zmi.asc | gpg --import" // Fingerprint: AC19 F9D5 36ED CD8A EF38 500E CE14 91F7 1C12 09B4 // Keyserver: wwwkeys.eu.pgp.net Key-ID: 1C1209B4 --nextPart3296521.54puIVQzs9 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEABECAAYFAkmk5+sACgkQzhSR9xwSCbQ2XgCdGbHavPxch1kQmBVaWRoMnls0 5lsAoNj9i06sEO3xvLYgvObWAJWVFnfq =e6H0 -----END PGP SIGNATURE----- --nextPart3296521.54puIVQzs9-- --===============6330066388149676925== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs --===============6330066388149676925==--