Symptom
After a LUN is replaced (the new LUN uses the same host ID as the original LUN), the information about the new LUN cannot be updated.
Root Cause
The LUN is not updated on the host.
Solution
Perform the following operations to remove or change the mapping of a LUN used by Red Hat hosts:
Before removing or changing LUN mapping on the storage system, stop all services running on the disk mapped by the LUN.
On DeviceManager, unmap the LUN.
Scan for LUNs on the host.
Run the multipath –ll command on the host. Find and record the name of the multipath disk (mpathX) corresponding to the unmapped LUN and the physical path (sdX).
Run the multipath -f mpathX command to delete the multipath disk identified in 4.
Run the echo 1 > /sys/block/sdX/device/delete command to delete the physical path identified in 4.
On DeviceManager, map a new LUN to the host.
Scan for LUNs on the host and reconfigure services.
