Requirements for external storage system maintenance
You must have the Storage Administrator (Provisioning) role. Before making changes to the external system, you must disconnect the external system and delete external volume mapping. After you have completed the changes, you can reconnect the system and remap the external volume.
You must remove and remap the external volume before making any of the following changes to the external system:
Changing WWNs/iSCSI target names of all target ports that connect to the local storage system
Changing the serial number of the external system
Changing LUNs of volumes in the external system
Reducing the volume capacity of the external volume
Modifying a host that is directly connected to a external storage system.
To modify the WWNs/iSCSI target names of some target ports connected to the local storage system, you do not need to release volumes mapped to the local storage system.