38 BladeSymphony 1000 Architecture White Paper www.hitachi.com
power redundancy, it boots the system after issuing a warning by illuminating the Warning LED. Hot
swapping is not possible in the absence of redundant power.
Redundant Cooling Fan Modules
The Cooling Fan Modules cool the system with variable speed fans, and are installed redundantly, as
illustrated in Figure27. The fans cool the system by pulling air from the front of the chassis to the back.
The modules can be hot-plugged, enabling a failed Cooling Fan Module to be replaced without
disrupting system operations. Cooling Fan Modules support the following functions:
• Control rotation
• Detect abnormal rotation
• Indicate the faulty location with LEDs
• Built-in fuse
Figure27. Top view and cooling fan modules numbers
Cooling fan 0 Cooling fan 1
Cooling fan 2 Cooling fan 3
0
Server blade slot No.
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
PCI slot No.