Emerson AXP1406 Manuel D’Utilisation
Adaptive Adjustment of the Minimum Fan Level
System Behavior in Response to Sensor Events
AXP1406/AXP1600 Subsystem IPMI Programmer’s Reference (6806800B66C)
143
The following graph illustrates the behavior of the above cooling algorithm in finding a stable
fan level in real shelf, in the presence of a substantial thermal load in the shelf. The
configuration parameter NORMAL_STABLE_TIME* is set to 30 minutes. The graph presents
the fan speed changes over a period of 70 minutes. The horizontal axis has time scaled from 0
to 70 minutes.
fan level in real shelf, in the presence of a substantial thermal load in the shelf. The
configuration parameter NORMAL_STABLE_TIME* is set to 30 minutes. The graph presents
the fan speed changes over a period of 70 minutes. The horizontal axis has time scaled from 0
to 70 minutes.
The fan speed is initially lowered to 3. This causes a thermal alert and after a single increase
in fan speed, during the subsequent fan speed reduction, the level stabilizes at 4. After the
expiration of a period defined by the parameter NORMAL_STABLE_TIME* (which is equal to
30 minutes) the level is lowered to 3 which again causes a thermal alert, an increase in fan
speed with subsequent reductions, and the fan level again stabilizes at 4.
in fan speed, during the subsequent fan speed reduction, the level stabilizes at 4. After the
expiration of a period defined by the parameter NORMAL_STABLE_TIME* (which is equal to
30 minutes) the level is lowered to 3 which again causes a thermal alert, an increase in fan
speed with subsequent reductions, and the fan level again stabilizes at 4.
* These are configurable options in /etc/shelfman.conf. If these values are not defined in
shelfman.conf, default levels are used.
shelfman.conf, default levels are used.
Figure A-1
Cooling Algorithm