sudo hdparm -B /dev/sda 可见硬盘/dev/sda的APM_level值为254,表示硬盘性能最大化,这需要保持高水平的硬盘转速,硬盘发热量自然就大.
如果返回/dev/sda: APM_level = not supported,则表示你的硬盘不支持APM(高级电源管理).
APM_level的全称为Advanced Power Management level,即(硬盘)高级电源管理级别.
man hdparm 可见:
Get/set Advanced Power Management feature, if the drive supports it.
A low value means aggressive power management and a high value means better performance.
Possible settings range from values 1 through 127 (which permit spin-down), and values 128 through 254 (which do not permit spin-down).
The highest degree of power management is attained with a setting of 1, and the highest I/O performance with a setting of 254.
A value of 255 tells hdparm to disable Advanced Power Management altogether on the drive (not all drives support disabling it, but most do).
