Entry tags:

advogato, ubuntu

Linux-hero wrote about how Ubuntu kills your hard drive. The situation is somewhat less clear than you might think from the article, but the basic takeaway message is that Ubuntu doesn't touch your hard drive power management settings by default. In almost all cases, it's more likely to be your BIOS or the firmware on your hard drive.

The script that's executed when you plug or unplug your laptop is /etc/acpi/power.sh. The relevant sections are:

function laptop_mode_enable {
...
    $HDPARM -S $SPINDOWN_TIME /dev/$drive 2>/dev/null
    $HDPARM -B 1 /dev/$drive 2>/dev/null
}

That is, when the laptop_mode_enable function is called, we set the drive power parameters. Now, by default laptop_mode_enable isn't called:

if [ x$ENABLE_LAPTOP_MODE = xtrue ]; then
    (sleep 5 && laptop_mode_enable)&
fi

because ENABLE_LAPTOP_MODE is false in the default install (check /etc/default/acpi-support). This means that, by default, we do not alter the hard drive power settings. In other words, the APM settings that your drive is using in Ubuntu are the ones that your BIOS programmed into it when the computer started. This is supported by the fact that people see this issue after resuming from suspend. We don't touch the hard drive settings at that point, so the only way it can occur is if your BIOS or drive default to this behaviour.

If you enable laptop mode, then we will enable aggressive power management on the drive and that may lead to some reduction in hard drive lifespan. That's a fairly inevitable consequence of laptop mode, since it only makes sense if the laptop enages in aggressive power management. But, as I said, that's not the default behaviour of Ubuntu.

There's certainly an argument that we should work around BIOSes, but in general our assumption has been that your hardware manufacturer has a better idea what your computer is capable of than we do. If a laptop manufacturer configures your drive to save power at the cost of life expectancy, then that's probably something you should ask your laptop manufacturer about.

193 Load_Cycle_Count        0x0012   060   060   000    Old_age   Always  -  600690

=== START OF INFORMATION SECTION ===
Model Family:     Hitachi Travelstar 7K60
Device Model:     HTS726060M9AT00
Serial Number:    MRH403M4GA7RHB
Firmware Version: MH4OA6BA
User Capacity:    60,011,642,880 bytes
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   6
ATA Standard is:  ATA/ATAPI-6 T13 1410D revision 3a
Local Time is:    Thu Nov  1 09:03:54 2007 EDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled