Administrator's Guide

Table 11 SAS I/O module LEDs status
StatusDescriptionItem
Green* = HealthySAS Port 11, 2
Amber = Issue
Green* = HealthySAS Port 23, 4
Amber = Issue
Green = HealthyOverall I/O module status5, 6
Amber = Issue
Green* = HealthySAS Port 37, 8
Amber = Issue
Green* = HealthySAS Port 49, 10
Amber = Issue
*If there is anything connected to a connector, the corresponding green LED is on and blinks off with activity. If there
is nothing connected to a connector, both LEDs are off.
Figure 43 Fan LEDs
The two fan modules are physically identical, but their control is not. The Fault/health LED on FAN
1 is a single bi-color LED controlled by the EMU via the Health Monitor – it is either off, steady
green, or flashing amber. The lens of the fan LED is colorless and looks grayish-white when off.
System Fan — Fan 1
Fan 1 LED is driven by the EMU firmware. The fan microprocessor inside the Fan module cannot
sense or control this LED. If the EMU fails, or if the connection between the EMU and the fan fails,
the LED cannot be controlled and thus may not reflect actual state. Also, because Fan 1 LED has
no power unless enclosure power is on, the EMU cannot indicate Fan status in standby mode.
There is no autonomic hardware circuit controlling the FAN Fault LED. Assuming the LED is working,
it flashes Amber by the EMU if one or two of the 3 fan rotors is not functioning, or if the
microprocessor on the fan module is unresponsive, or if code on the module is unreadable.
Drive Fan — Fan 2
The Fault/health LED on FAN 2 is not controlled at all by the EMU – but is controlled by one of
the management processors inside the SAS I/O Module. This LED cannot be lit unless enclosure
power is on, and its state depends upon signals from one of the SAS I/O modules.
To troubleshoot a degraded fan, you can use the EMU CLI commands SHOW ENCLOSURE STATUS
and SHOW ENCLOSURE FAN ALL described in “Managing the EMU” (page 134).
54 Monitoring and troubleshooting the messaging system