From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bernd Zeimetz Subject: multipath + evms problems Date: Sat, 29 Oct 2005 12:48:50 +0200 Message-ID: <200510291248.51290.bernd@bzed.de> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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: device-mapper development List-Id: dm-devel.ids Hi, we have some trouble with runnign an EMC CX400 with multipath and evms. If we run the machine with systemtype 0x16 (it identifies itself as FSC FC66 then), Arraycommpath = 0 and Failovermode = 2, failover seems to work well (not much tested), and evms uses the dm/multipath devices. The bad thing on this way is a trespass of the LUNs every few seconds, which is not the way it should work. Setting the machine to something useful - systemtype=3 (==DGC), arraycommpath=1, failovermode=1 - it is recognized by multipath-tools and dm-emc as emc-machine. With zeus-1:/# cat /etc/multipath.conf defaults { path_grouping_policy failover no_path_retry queue } multipaths { multipath { wwid 3600601f2a20c0000fa13caa656b0d711 alias LUN_0 } [....] multipath { wwid 3600601f4a20c000099dc229956b0d711 alias LUN_7 } } we have some nice devices: zeus-1:/# ll /dev/mapper/ total 0 brw------- 1 root root 254, 0 Oct 29 12:09 LUN_0 brw------- 1 root root 254, 4 Oct 29 12:09 LUN_0p1 [....] brw------- 1 root root 254, 2 Oct 29 12:09 LUN_7 brw------- 1 root root 254, 13 Oct 29 12:09 LUN_7p1 crw-rw---- 1 root root 10, 63 Oct 29 12:08 control zeus-1:/# but evms does not use them, it directly accesses and uses sd* zeus-1:/# ll /dev/evms [...] drwxr-xr-x 2 root root 60 Oct 29 12:09 dm brw-r----- 1 root disk 8, 0 Oct 29 12:09 sda brw-r----- 1 root disk 8, 16 Oct 29 12:09 sdb brw-r----- 1 root disk 8, 32 Oct 29 12:09 sdc brw-r----- 1 root disk 8, 48 Oct 29 12:09 sdd brw-r----- 1 root disk 8, 64 Oct 29 12:09 sde brw-r----- 1 root disk 8, 80 Oct 29 12:09 sdf brw-r----- 1 root disk 8, 96 Oct 29 12:09 sdg brw-r----- 1 root disk 8, 112 Oct 29 12:09 sdh Of course this results in a not working failover - this should work without using multipath at all. After excluding the sd* devices in evms.conf it doesn't find any evms-devices at all. We also have a ton of multipathd: uevent trigger error messages in the daemon's log. Operating system is Debian sarge, but with kernel 2.6.14, the actual git version of the multipath-tools, evms 2.5.3, udev 0.070, libdevmapper/dmsetup 1.01.04. Since this behaviour seems to depend on the use of the emc-hwhandler/dm-emc I'm posting to this list. Hope you have any ideas how to fix it, or do we run in an evms-only bug here? Greetings from Darmstadt, Germany Bernd Zeimetz Darmstadt University of Technology