Can you let me know the iDRAC FW version installed on the server. You need to use following command to set BIOS Boot mode. This command attribute value is case sensitive racadm set BIOS.BiosBootSettings.BootMode Bios
Good day,  I try to run through the ssh the following command racadm set BIOS.BiosBootSettings.BootMode BIOS  and I get the following error ERROR: RAC947: Invalid object value specified.       Make sure to specify the value depending on the type of object.       For more information, see RACADM help. if I run racadm get BIOS.BiosBootSettings.BootMode I can see the current value. I have try BIOS,bios, Bios but no luck..  Any help? 
iDRAC7 error in cli command