HP ProLiant ML370 G5 Server - Manual (Page 16)

Component identification 16
HP recommends populating hard drive bays starting with the lowest SAS or SATA device number.
SAS and SATA hard drive LEDs
Item Description Status
1 Fault/UID LED Amber = Drive failure
Flashing amber = Fault-process activity
Blue = Unit identification is active
Off = No fault-process activity
2 Online/activity LED Green = Drive activity
Flashing green = High activity on the
drive or drive is being configured as part
of an array
Off = No drive activity