Comment 232 for bug 59695

Revision history for this message
ubuntu_demon (ubuntu-demon) wrote :

to Bart Samwel :

Since it's currently impossible to recommend to turn laptop_mode on by default I'm currently recommending this to people who are heavily affected :
* use apm 128 while on battery (most head parks, best protection from bumps, lower power usage)
* use apm 254 while on AC (no protection from bumps,no head parks,best performance,increased heat)

The biggest reason to do so would be to protect the harddisk from bumps. Even if the laptop is used on battery everyday for four hours the Load_Cycle_Count would have to increase with 137 per hour to be able to reach 600.000 within three years of usage. Most people don't see their Load_Cycle_Count increase that fast (although some might). Most people don't use their laptop for four hours on battery each day. Those people who are afraid they will still reach the maximum Load_Count as specified by their manufacturer within three years of usage do need to tweak the "apm number while on battery".

This won't interfere with people who are using laptop-mode since laptop-mode doesn't touch apm but only spindown.

In my humble opinion you should consider doing something similar in acpi-support.

The full HOWTO for this ugly unofficial fix :
http://ubuntuforums.org/showpost.php?p=3675960&postcount=26

The interesting part of the HOWTO :

99-hdd-ugly-fix.sh :
========================
#/bin/bash
if on_ac_power = 1 ; then
hdparm -B 254 /dev/sda
else
# possibly on battery
hdparm -B 128 /dev/sda
fi
=========================

$sudo install 99-hdd-ugly-fix.sh /etc/acpi/suspend.d/
$sudo install 99-hdd-ugly-fix.sh /etc/acpi/resume.d/
$sudo install 99-hdd-ugly-fix.sh /etc/acpi/start.d/
$sudo install 99-hdd-ugly-fix.sh /etc/acpi/ac.d/
$sudo install 99-hdd-ugly-fix.sh /etc/acpi/battery.d/

=========================

The first post of the support thread :
http://ubuntuforums.org/showpost.php?p=3733762&postcount=1

The support thread :
http://ubuntuforums.org/showthread.php?t=591503