Comment 83 for bug 952556

hdparm is contradicting itself in /usr/lib/pm-utils/power.d/95hdparm-apm (Using LMDE+UP5, kernel 3.2+45, hdparm 9.39-1+b1)

$ head /usr/lib/pm-utils/power.d/95hdparm-apm

#! /bin/sh
#
# This script adjusts hard drive APM settings using hdparm. The hardware
# defaults (usually hdparm -B 127) 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 127, because the head parking is
# very useful for shock protection.
#
# Refactored from acpi-support's 90-hdparm.sh for pm-utils

It is obviously confusing -B 127 (which permits spin-down) with APM (-B 128) permitting PM (including head-parking) but not spin-down.

For instance, on my WD Scorpio Blue WD10JPVT, which had idle3 in its firmware modified from default 8sec to 180sec (3min) using `idle3ctl` (or wdidle3 in DOS!), I'm parking at an acceptable rate with the default PM level of 128, when on battery, without spin-downs, just as I wanted.

# hdparm -I /dev/sda | grep Advanced
 Advanced power management level: 128
    * Advanced Power Management feature set

# hdparm -I /dev/sda | grep -i standby
 Standby timer values: spec'd by Standard, with device specific minimum