[dm-devel] [fail][unknown] error on multipath

Would like to seek support on my current problem. We are currently running a NFS server on a clustered environment under RHEL 5.6. LUN disks are being presented into both cluster nodes via DM-Multipathing which is being used as NFS share. However, everytime I am testing NFS package failover, failover always fails and upon checking the multipath (multipath -ll), it shows that the LUN disk affected has "[fail][unknown]" error. The only workaround that is being done is to present/unpresent the LUN disk to have it [ready][undef] state.