Thanks!
There is another way to check SN and ESN.
Log in to the OMU portal as the admin user.
Choose License > View SN and ESN.
The tab page shown in Figure 1 is displayed.
Figure 1 Obtaining the SN and ESN

Select a node from the system domain list on the left pane and click Obtain SN and ESN.
The SN and ESN of the server are displayed.
Click Export to export the obtained SN and ESN.