
In HP-UX, we can use command cstm to check the system serial number. cstm is installed with the OnlineDiagnostics / Support Tools Bundle on HP-UX 9000 systems.
# echo "sc product system;info;wait;il" | cstm | grep -i "system serial" System Serial Number...: ABC1234DE
or
# echo "sel path system\ninfolog\nexit"|cstm|grep "System Serial" System Serial Number...: ABC1234DE
For HP-UX 11i the following command also works:
# getconf MACHINE_SERIAL ABC1234DE
And for HP-UX 11i v2 on Itanium-based systems, use the machinfo command:
# machinfo | grep "machine serial" machine serial number = ABC1234DE

