From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erez Zilber Subject: Running open-iscsi with device mapper hangs Date: Tue, 09 May 2006 17:00:20 +0300 Message-ID: <4460A074.6030805@voltaire.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: open-iscsi@googlegroups.com, device-mapper development List-Id: dm-devel.ids Hi, I'm trying to run open-iscsi with the multipath tool. I was able to=20 create a scenario in which the initiator machine hangs: My initiator runs on a SLES 10 beta 8 machine. The db contains 2 targets: iscsiadm -m node [83347a] 192.168.10.106:3260,1 iqn.2005-12.com.voltaire.206000C0FF07C1D1 [030479] 192.168.10.105:3260,1 iqn.2005-12.com.voltaire.206000C0FF07C1D1 Loading the dm modules: salt:~ # modprobe dm-mod; modprobe dm-multipath I start the initiator: salt:~ # /etc/init.d/open-iscsi start Starting iSCSI initiator service: done Logging into iqn.2005-12.com.voltaire.206000C0FF07C1D1: done Logging into iqn.2005-12.com.voltaire.206000C0FF07C1D1: done salt:~ # sg_map -i -x /dev/sg0 0 0 0 0 0 /dev/sda DotHill SANnet II FC 411I /dev/sg1 1 0 0 0 0 /dev/sdb DotHill SANnet II FC 411I Now, I start the multipath daemon: salt:~ # ls /dev/mapper/ control salt:~ # multipathd salt:~ # ls /dev/mapper/ control mpath0 salt:~ # multipath -l mpath0 (3600c0ff00000000007c1d121c397f503) [size=3D10 GB][features=3D0][hwhandler=3D0] \_ round-robin 0 [prio=3D0][active] \_ 0:0:0:0 sda 8:0 [active][undef] \_ round-robin 0 [prio=3D0][enabled] \_ 1:0:0:0 sdb 8:16 [active][undef] Running some traffic: salt:~ # dd if=3D/dev/mapper/mpath0 of=3D/dev/null count=3D500000 500000+0 records in 500000+0 records out 256000000 bytes (256 MB) copied, 9.54608 seconds, 26.8 MB/s Now, I disconnect (unplug the cable) the target which is represented by=20 /dev/sda and run another dd command: salt:~ # dd if=3D/dev/mapper/mpath0 of=3D/dev/null count=3D500000 500000+0 records in 500000+0 records out 256000000 bytes (256 MB) copied, 199.601 seconds, 1.3 MB/s Now, the 1st priority group has failed: salt:~ # multipath -l mpath0 (3600c0ff00000000007c1d121c397f503) [size=3D10 GB][features=3D0][hwhandler=3D0] \_ round-robin 0 [prio=3D0][enabled] \_ 0:0:0:0 sda 8:0 [failed][faulty] \_ round-robin 0 [prio=3D0][active] \_ 1:0:0:0 sdb 8:16 [active][undef] I reconnect the target and it's back to life: salt:~ # multipath -l mpath0 (3600c0ff00000000007c1d121c397f503) [size=3D10 GB][features=3D0][hwhandler=3D0] \_ round-robin 0 [prio=3D0][enabled] \_ 0:0:0:0 sda 8:0 [active][undef] \_ round-robin 0 [prio=3D0][active] \_ 1:0:0:0 sdb 8:16 [active][undef] I stop the initiator and the machine hangs: salt:~ # /etc/init.d/open-iscsi stop Logging out from iqn.2005-12.com.voltaire.206000C0FF07C1D1: done Logging out from iqn.2005-12.com.voltaire.206000C0FF07C1D1: (now the=20 machine is dead) I know that the device mapper was tested in the past. Was this scenario=20 tested? Is anyone able to reproduce this behavior? I was able to=20 reproduce it 5 times in a row. Thanks --=20 ____________________________________________________________ Erez Zilber | 972-9-971-7689 Software Engineer, Storage Team Voltaire =96 _The Grid Backbone_ __ www.voltaire.com