Fixing Ubuntu HardDisk Power Management Bug

A bug on ACPI system of Ubuntu could lead to shortening harddisk life on Laptop. According to Paul’s investigation The major issue seems to be the load/unload system that is integrated into laptop hard drives nowadays. The heads will automatically be retracted (parked) after some idle time to decrease the risk of shock damage and reduce power consumption.

When switching to battery power, /etc/acpi/power.sh issues the command hdparm -B 1 to all block devices. This leads to extremely frequent load cycles. Many laptop drives are rated as coping with 600,000 cycles per lifetime (some even less). So even -B 160 leads to 3 cycles per minute (180 per hour), leading to a
lifespan of 600,000 / 180 / 24= 139 days (of continuous battery powered use). That means you’d need a new hard drive every 417 days.

To fix this problem add this line on /etc/hdparm.conf

/dev/sda {
apm = 255
}

Then create a file /etc/acpi/resume.d/99-stop-thinkpad-madness.sh
with the following contents:
#!/bin/sh
hdparm -B 255 /dev/sda

This bug fix is following Gilles’ posting on launcpad.net