What do different values of hard drive's Advanced Power Management feature (hdparm -B) affect, except spin-down?
hdparm's -B parameter is documented as: Get/set Advanced Power Management feature, if the drive supports it. A low value means aggressive power management and a high value means better per‐ ...
These two options seem confusing. For example: according to the man page -B 254 "does not permit spin-down". However, testing with -B 254 -S 1 the drive does spin down after 5 seconds. -B ...