SUPER MICRO Computer SUPERSERVER 6014L-T - Manual (Page 31)

Chapter 3: System Interface
3-3
Power: Indicates power is being supplied to the system's power supply units.
This LED should normally be illuminated when the system is operating.
3-4 Serial ATA Drive Carrier LED
Each Serial ATA drive carrier has a green LED. When illuminated, this green LED
(on the front of the Serial ATA drive carrier) indicates drive activity. A connection to
the Serial ATA backplane enables this LED to blink on and off when that particular
drive is being accessed.