Bernd/All, Some additional infos: I unplugged the fc cable from fabric a and rebooted. When checking dmesg I noticed that there were not any dm-emc parameters loaded like there were in my previous email below when rebooting with both cables connected. xen2:~ # dmesg |grep -i device-mapper device-mapper: 4.5.0-ioctl (2005-10-04) initialised: dm-devel@xxxxxxxxxx device-mapper: dm-multipath version 1.0.4 loaded device-mapper: dm-round-robin version 1.0.0 loaded device-mapper: dm-multipath: error getting device device-mapper: error adding target to table xen2:~ # Am I missing some setup somewhere for a dual port hba? Thanks, John Begin forwarded message: Date: Fri, 8 Sep 2006 11:32:32 -0400 From: John Little <jslittl@xxxxxxxxxxxxx> To: dm-devel@xxxxxxxxxx Subject: Re: Multipath and SAN Fabric failover Hi Bernd I commented out everything including the blacklist in the multipath.conf as you suggested. When I unplug the fc cable from fabric a the filesystem goes into read only mode. multipath -v2 -d shows the same errors previously noted. After rebooting I unplugged the fc cable from fabric b. The file system properly stays in read\write mode. Just to make sure that I've covered everything I partitioned the disk as /dev/sdc and then used lvm2 command: pvcreate /dev/disk/by-name/capsprod-part1 to initialize and use the partition with lvm. I found the following error in dmesg: device-mapper: 4.5.0-ioctl (2005-10-04) initialised: dm-devel@xxxxxxxxxx dm-netlink version 0.0.2 loaded device-mapper: dm-multipath version 1.0.4 loaded device-mapper: dm-round-robin version 1.0.0 loaded device-mapper: dm-multipath: error getting device<====error device-mapper: error adding target to table<====error device-mapper: dm-emc version 0.0.3 loaded device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: long trespass command will be send device-mapper: dm-emc: emc_pg_init: sending switch-over command device-mapper: dm-emc: honor reservation bit will not be set (default) device-mapper: dm-emc: emc_pg_init: sending switch-over command Can you give me an idea of what else to check? I'm nowhere near an expert on this subject as just about everything I've learned has been from reading this list. A couple of questions come to mind: Is the lun not properly trespassing from fabric a to fabric b? Where does the directive [features=1 queue_if_no_path] come from when running multipath -v2 -d? Could this be the problem? Thanks, John >Heya, >I think you should just try an empty multipath.conf, only put the >blacklist in. The EMC CX needs pp_emc as prio callout for example. The >defaults within >multipath should just work. Also make sure your >failovermode and arraycommpath are both set to 1. A few hints are >mentioned on >>http://christophe.varoqui.free.fr/wiki/wakka.php?wiki=TestedEnvironments >Please fill in if you find something that's missing there. >Best regards, >Bernd Zeimetz >>John Little wrote: >> Hi all, >> I am trying to setup our server so that we have fabric failover >> from >> the san. However my file sytem comes up read-only when I pull a cable >> for testing. >> I am using the following: >> SLES 10 >> multipath-tools-0.4.6-25.8 >> q-logic 2342 dual port hba >> emc cx600 san >> (4) McData DS-24 switches (2 for fabric a and 2 for fabric b) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
