mam dojem, ze nekdy tenhle tejden se mi to stahlo viz /etc/acpi/*/90-hdparm.sh
#! /bin/sh
#
# This script adjusts hard drive APM settings using hdparm. The hardware
# defaults (usually hdparm -B 128) cause excessive head load/unload cycles
# on many modern hard drives. We therefore set hdparm -B 254 while on AC
# power. On battery we set hdparm -B 128, because the head parking is
# very useful for shock protection.
#