From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758275AbZJHOkv (ORCPT ); Thu, 8 Oct 2009 10:40:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932352AbZJHOku (ORCPT ); Thu, 8 Oct 2009 10:40:50 -0400 Received: from 82-117-125-11.tcdsl.calypso.net ([82.117.125.11]:45132 "EHLO smtp.ossman.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756453AbZJHOkl (ORCPT ); Thu, 8 Oct 2009 10:40:41 -0400 Date: Thu, 8 Oct 2009 16:39:52 +0200 From: Pierre Ossman To: neilb@suse.de, LKML Subject: Raid not shutting down when disks are lost? Message-ID: <20091008163952.679572b5@mjolnir.ossman.eu> X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.6; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; protocol="application/pgp-signature"; boundary="=_freyr.ossman.eu-19831-1255012805-0001-2" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a MIME-formatted message. If you see this text it means that your E-mail software does not support MIME-formatted messages. --=_freyr.ossman.eu-19831-1255012805-0001-2 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Today one RAID6 array I manage decided to lose four out of eight disks. Oddly enough, the array did not shut down but instead I got intermittent read and writer errors from the filesystem. It's been some time since I had a failure of this magnitude, but I seem to recall that once the array lost too many disks, it would shut down and refuse to write a single byte. The nice effect of this was that if it was a temporary error, you could just reboot and the array would start nicely (albeit in degraded mode). Has something changed? Is this perhaps an effect of using RAID6 (I used to run RAID5 arrays)? Or was I simply lucky the previous instances I've had? Related, it would be nice if you could control how it handles lost disks. E.g. I'd like it to go read-only when it goes in to fully degraded mode. In case the last disk lost was only a temporary glitch, the array could be made to recover without a lengthy resync. Rgds --=20 -- Pierre Ossman WARNING: This correspondence is being monitored by the Swedish government. Make sure your server uses encryption for SMTP traffic and consider using PGP for end-to-end encryption. --=_freyr.ossman.eu-19831-1255012805-0001-2 Content-Type: application/pgp-signature; name="signature.asc" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.12 (GNU/Linux) iEYEARECAAYFAkrN+cEACgkQ7b8eESbyJLj+BwCgiM5J62B3tGzVDPBXSif1Yoni HfIAoJHH3s96/hKsnSXODxAqwxR6kbco =NCMf -----END PGP SIGNATURE----- --=_freyr.ossman.eu-19831-1255012805-0001-2--