This article explains how to view the hardware serial number in EMC Elastic Cloud Search (ECS). There is a difference between the License Serial number and the Hardware Serial number.
OnCommand Insight (OCI) always displays the License Serial Number of ECS.
In EMC ECS, we have the following information:
PSNT = Hardware serial number
SWID = License serial number
ECS uses the SWID as the identifier on how storage nodes are identified. The SWID is also visible in OCI as the serial number; this is the License serial number.