If a LUN that was presented to an ESX host was deleted on the SAN without removing it from the host first, failover errors are now seen in the vmkernel.  You can remove the dead path by entering the following command.

esxcfg-rescan -d vmhba<X> # where vmhba<X> is your iSCSI vmhba



Title: VMware Clustering; How to remove a dead path to an iSCSI storage system.

If a LUN that was presented to an ESX host was deleted on the SAN without removing it from the host first, failover errors will occur and can be viewed in the vmkernel.  You can remove the dead path by entering the following command from the terminal prompt.

esxcfg-rescan -d vmhba<X> # where vmhba<X> is your iSCSI vmhba