运营商地市局点，受制于设备机房条件，毗邻居民区，夏天常被客户投诉噪音过大，客户问是否有办法优化。
客户无加装空调的条件，要求设备尽量降低风扇旋转的噪声
V9设备支持一个静音降速命令，通过将风扇调速曲线的低温点提高，以此来降低部分转速达到降低噪声的目的，如果温度上升，转速会再次提高来散热，实验室下发结果如下：
设置静音：[H3C-probe]debug sysm set-fan-quiet
取消静音：[H3C-probe]debug sysm undo-fan-quiet
1. 静音命令下发前设备两个风扇的稳定转速：
Fan Speed(rpm)
--- ----------
1 7492
2 7447
Fan Speed(rpm)
--- ----------
1 6750
2 6524
[ZJHZQTXS_A9_204-C-01-40.UCORE-0-0]dis environment
System temperature information (degree centigrade):
----------------------------------------------------------------------
Slot Sensor Temperature Lower Warning Alarm Shutdown
0 hotspot 1 56 0 75 90 95
0 hotspot 2 41 0 75 90 95
0 hotspot 3 38 0 75 90 95
0 hotspot 4 64 0 75 90 95
0 chip 0 71 0 88 102 110
0 chip 0 71 0 88 102 110
0 chip 0 66 0 88 102 110
0 cpu 1 50 0 88 96 104
4 inflow 1 28 0 48 60 NA
4 hotspot 1 30 0 75 90 NA
4 hotspot 2 34 0 75 90 NA
4 cpu 1 41 0 102 102 NA
5 inflow 1 29 0 48 60 NA
5 hotspot 1 32 0 75 90 NA
5 hotspot 2 32 0 75 90 NA
5 cpu 1 49 0 102 102 NA
6 hotspot 1 40 0 75 90 95
6 chip 0 51 0 88 102 110
6 hotspot 2 35 0 75 90 95
6 chip 0 45 0 88 102 110
6 cpu 1 39 0 88 96 104
7 hotspot 1 44 0 75 90 95
7 chip 0 53 0 88 102 110
7 hotspot 2 38 0 75 90 95
7 chip 0 46 0 88 102 110
7 cpu 1 42 0 88 96 104
2. 下发命令行后的风扇转速基本稳定时如下，单个扇叶最低最高转速会有100-300rpm左右的波动
<H3C>dis fan
Fan-tray 1:
Fan Speed(rpm)
--- ----------
1 6799
2 6720
Fan-tray 2:
Fan Speed(rpm)
--- ----------
1 6127
2 6105
<H3C>dis environment
System temperature information (degree centigrade):
----------------------------------------------------------------------
Slot Sensor Temperature Lower Warning Alarm Shutdown
0 hotspot 1 58 0 75 90 95
0 hotspot 2 41 0 75 90 95
0 hotspot 3 38 0 75 90 95
0 hotspot 4 65 0 75 90 95
0 chip 0 74 0 88 102 110
0 chip 0 73 0 88 102 110
0 chip 0 68 0 88 102 110
0 cpu 1 51 0 88 96 104
4 inflow 1 27 0 48 60 NA
4 hotspot 1 30 0 75 90 NA
4 hotspot 2 34 0 75 90 NA
4 cpu 1 42 0 102 102 NA
5 inflow 1 29 0 48 60 NA
5 hotspot 1 32 0 75 90 NA
5 hotspot 2 32 0 75 90 NA
5 cpu 1 49 0 102 102 NA
6 hotspot 1 40 0 75 90 95
6 chip 0 51 0 88 102 110
6 hotspot 2 34 0 75 90 95
6 chip 0 44 0 88 102 110
6 cpu 1 40 0 88 96 104
7 hotspot 1 44 0 75 90 95
7 chip 0 53 0 88 102 110
7 hotspot 2 38 0 75 90 95
7 chip 0 47 0 88 102 110
7 cpu 1 43 0 88 96 104