To reverse fans in server hardware:
Launch PuTTy
Select "Serial" as Connection Type
Click "Open"
Automatic configuration is running, press CTRL_C or CTRL_D to break.
Enter
ctrl+C or Ctrl D
system
System View: return to User View with Ctrl+Z.
[HP]fan prefer-direction slot 1 port-to-power
[HP]%Jan 1 00:03:32:322 2011 HP DEV/5/FAN_RECOVERED: Fan 1 recovered.
%Jan 1 00:03:32:323 2011 HP DEV/5/FAN_RECOVERED: Fan 2 recovered.
[HP]dis fan
Slot 1
FAN 1
State : Normal
Wind Direction :Port-to-Power
Prefer Wind Direction :Port-to-Power
FAN 2
State : Normal
Wind Direction :Port-to-Power
Prefer Wind Direction :Port-to-Power
[HP]