From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Becker Subject: EMC Clariion ghost devices Date: Fri, 29 Jul 2005 15:28:03 -0700 Message-ID: <20050729222803.GS16618@ca-server1.us.oracle.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: christophe varoqui Cc: dm-devel@redhat.com List-Id: dm-devel.ids Christophe, I've just tried using the multipath-tools (SLES9 SP2, multipath-tools-0.4.4-0.22) with my EMC clariion. Now, this clariion is an active/passive system, and the second path is showing a ghost LUN 0 (this is expected). During normal boot, the device (/dev/sdap) returns an I/O error when the kernel tries to get the partition table. No problem. If later someone scans the disk, they get an I/O error. No problem. Then I fire up multipathd and multipath. Multipath creates a dm device for the ghost, and tries to run kpartx on it. That kpartx hangs. In fact, I don't know how, but it ends up in a frozen I/O state. It's unkillable. I'd expect an I/O error, but no, it just plain doesn't exit. Ditto any other access to the associated dm. Now, is this a dm problem (the device not seeing the error and returning it)? Is it a multipath problem (multipath should notice the ghost and not try to dm it)? Is it a configuration problem (I should somehow know which name the ghost got, and configure multipath to ignore it)? Joel -- Life's Little Instruction Book #182 "Be romantic." Joel Becker Senior Member of Technical Staff Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127