Here's what SMART tells me the serial number is:
=== START OF INFORMATION SECTION ===
Device Model: Hitachi HDS721010CLA332
Serial Number: JP2940HQ3ZY7KH
Firmware Version: JP4OA3EA
User Capacity: 1,000,204,886,016 bytes
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: 8
ATA Standard is:&nb........