【Problem Description】：
In an RH2288H V3 equipped with a rear drive backplane, the fan speed is abnormal, reaching 80% of the maximum.
【Problem Analysis】：
1. No hardware alarm is reported, and no compatibility issue is found. High-power PCIe cards are not installed.
2. The inlet temperature reaches 34ºC.
3. The server is configured with a rear drive backplane. According to the fan speed adjustment policy, the fan speed reaches 80% of the maximum if the temperature is higher than 35ºC.
4. When the inlet temperature is between 35ºC and 40ºC, the speed reaches 80% of the maximum and the hysteresis value is 2. Therefore, when the inlet temperature is 34ºC, the fan speed is still 80% of the maximum.
【Root Cause】：
The temperature in the equipment room is too high, and the fan speed increases, which is a normal phenomenon.
