When I mount an ocfs2 partition with the device mapper the mount command shows a /dev/dm-x device rather than a /dev/mapper device, but, I mount by label. Ex:
1. partition the drive -- fdisk /dev/dm-0 (or can use /dev/sdx) 2. reboot -- now have dm-0 and dm-1 3. format the partition -- mkfs.ocfs2 /dev/dm-1 -L myLabel .... /dev/dm-1 4. mount by label. fstab: LABEL=myLabel /somedir ocfs2 _netdev 0 0 5. reboot The mount command will show /dev/dm-1 as the mount point. This is the device shown by 'ls -al /dev/disk/by-label' to be associated to myLabel. This seems to work ok, if I pull a fibre connection the multipath command will show the failed path and communication will continue on another path. This could just be a Sles10 thing also ... -----Original Message----- From: ocfs2-users-boun...@oss.oracle.com [mailto:ocfs2-users-boun...@oss.oracle.com] On Behalf Of Elliott Perrin Sent: Thursday, March 18, 2010 9:58 PM To: ocfs2-users@oss.oracle.com Subject: Re: [Ocfs2-users] OCFS2 Multipath Configuration I have seen node fences occur on all of our OCFS2 systems when the O2CB_HEARTBEAT_THRESHOLD is set less than 31 on both FC and iSCSI connected systems. In some testing I have done I found that all nodes would panic with O2CB_HEARTBEAT_THRESHOLD set to any value less than 15 and we would see single node fencing with values between 15 and 30. With the O2CB_HEARTBEAT_THRESHOLD set to 31 or greater we do not see a fence occur when fabric disruption occurs, again on both iSCSI and FC. This is with a multipath configuration that includes polling_interval "5" no_path_retry "5" features "1 queue_if_no_path" failback "immediate" selector "round-robin 0" as some of the configuration variables used in the setup. As long as the output of mount (not mounted.ocfs2) shows that your file system mount is from a /dev/mapper created multipath device then OCFS2 is using the multipath provided device. > -----Original Message----- > From: ocfs2-users-boun...@oss.oracle.com [mailto:ocfs2-users- > boun...@oss.oracle.com] On Behalf Of Sunil Mushran > Sent: Thursday, March 18, 2010 2:11 PM > To: David Johle > Cc: ocfs2-users@oss.oracle.com > Subject: Re: [Ocfs2-users] OCFS2 Multipath Configuration > > Yeah.. mounted is a bit dumb. In the next release, it will recognize > /dev/mapper devices. We still need to teach it to handle multipathing > fully. > > David Johle wrote: > > I'm not sure about why mounted.ocfs2 is showing both the dm and the > > sd devices for the same volume. But this could all be very similar > > to a problem I've experienced with OCFS2 & mount finding the right > > device with multipathing. > > > > See the following thread for some more insight: > > http://oss.oracle.com/pipermail/ocfs2-users/2009-March/003391.html > > > > > > > > At 04:12 PM 3/15/2010, you wrote: > > > >> Date: Wed, 16 Dec 2009 14:20:45 -0500 > >> From: "Nyburg, Daryl" <daryl.nyb...@utoledo.edu> > >> Subject: [Ocfs2-users] OCFS2 Multipath Configuration > >> To: <ocfs2-users@oss.oracle.com> > >> > >> Hello All, > >> I am having some problems configuring OCFS2 to use only the > >> multipath device name. We have been doing failover testing with our > >> ISCI SAN and as soon as we unplug one NIC the following messages > appear > >> in /var/log/messages and the system reboots. > >> > >> > >> Dec 16 12:39:03 mcprac01 kernel: (56,6):o2hb_write_timeout:172 > ERROR: > >> Heartbeat write timeout to device dm-34 after 120000 milliseconds > >> Dec 16 12:39:03 mcprac01 kernel: (56,6):o2hb_stop_all_regions:1967 > >> ERROR: stopping heartbeat on all active regions. > >> Dec 16 12:39:03 mcprac01 kernel: ocfs2 is very sorry to be fencing > this > >> system by restarting > >> > >> > >> RHEL 5.3 Kernel 2.6.18-128.el5 > >> OCFS2 Versions > >> ocfs2console-1.4.3-1.el5 > >> ocfs2-2.6.18-128.el5-1.4.2-1.el5 > >> ocfs2-tools-1.4.3-1.el5 > >> > >> Why does this show all device paths? Is there anyway to tell OCFS2 > to > >> ignore the /dev/sd* devices ? > >> $ mounted.ocfs2 -d > >> Device FS UUID > Label > >> /dev/sdf1 ocfs2 2eaddbd4-fac6-4c83-a86d-357215730b23 > >> /dev/dm-25 ocfs2 2eaddbd4-fac6-4c83-a86d-357215730b23 > >> /dev/sdaj1 ocfs2 2eaddbd4-fac6-4c83-a86d-357215730b23 > >> /dev/sdd1 ocfs2 199f76a6-280a-46c6-812e-50712170a823 > >> /dev/dm-32 ocfs2 199f76a6-280a-46c6-812e-50712170a823 > >> /dev/sdai1 ocfs2 199f76a6-280a-46c6-812e-50712170a823 > >> > > > > _______________________________________________ > > Ocfs2-users mailing list > > Ocfs2-users@oss.oracle.com > > http://oss.oracle.com/mailman/listinfo/ocfs2-users > > > > > _______________________________________________ > Ocfs2-users mailing list > Ocfs2-users@oss.oracle.com > http://oss.oracle.com/mailman/listinfo/ocfs2-users _______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-users _______________________________________________ Ocfs2-users mailing list Ocfs2-users@oss.oracle.com http://oss.oracle.com/mailman/listinfo/ocfs2-users