This is a disk protection user-space daemon. It monitors the acceleration values through the various motion interfaces and automatically initiates disk head parking if a fall or sliding of the laptop is detected.

Currently, the following motion interfaces are supported:

• HDAPS on IBM/Lenovo ThinkPads
• AMS on Apple iBooks and PowerBooks (G4)
• FREEFALL on Hewlett-Packard and DELL laptops
• HP3D on Hewlett-Packard laptops
• APPLESMC on Apple MacBooks and MacBooks Pro (Intel) (UNTESTED!)
• Toshiba HAPS and Toshiba ACPI on Toshiba laptops (UNTESTED!)
• Generic input/joystick on ACER laptops (UNTESTED!)

./configure
make
make install

The following parameters to ./configure are probably interesting:

• --with-systemdsystemunitdir lets you specify the directory for systemd unit files. It defaults to the output of pkg-config --variable=systemdsystemunitdir systemd.
• --with-udevdir lets you specify the directory for udev rules files. It defaults to the output of pkg-config --variable=udevdir udev.

• Arch and AUR
• Debian
• Gentoo
• Slackbuilds
• Ubuntu

In most cases, just running hdapsd as root should be enough, as it will try to autodetect everything itself.

If you want to adjust stuff, these are the most commonly used options:

• --cfgfile which allows to load a configuration from a file.
• --device which device to protect, e.g. --device=sda. Defaults to autodetection of all rotating devices.
• --sensitivity adjusts the sensitivity of the algorithmus. Defaults to 15.
• --adaptive enables adaptive mode, where hdapsd adjusts the sensitity while the mouse and keyboard are used.
• --background sends hdapsd into the background as a daemon.

For more options, please read man hdapsd.

hdapsd comes with systemd and udev integration. This means when those two are found on your system, misc/[email protected] and misc/hdapsd.rules are installed and used. udev will start one hdapsd instance for each rotational, non-removable disk it finds.

If you want to disable this automation for a certain disk, you can mask the systemd unit by calling:

systemctl mask hdapsd@sdX

If you want to disable this automation at all, you can create an empty /etc/udev/rules.d/hdapsd.rules, which will override the system-installed udev rule. You can still enable hdapsd for certain devices by creating [email protected] symlinks in /etc/systemd/system/multi-user.target.wants/

If you want to customize the parameters hdapsd is using, you can edit /etc/hdapsd.conf (preferred) or by customizing [email protected] in /etc/systemd/system/.

As an alternative, you could also use misc/hdapsd.service, which you'd have to install yourself. This unit will just start hdapsd the same way good old sysvinit would do.

Since kernel 2.6.28 you don't need to patch your kernel, as support for IDLE_IMMEDIATE is present in mainline.

NOTE: The new interface only allows IDLE_IMMEDIATE for drives that announce to be ATA-7 conform. But threre are also drives that support ATA-6 only but do IDLE_IMMEDIATE fine. For those you need to force the interface with: echo -1 > /sys/block/$DISK/device/unload_heads. Or you can call hdapsd like this: hdapsd -f -d $DISK, to achieve the same result.

For kernels <2.6.28, please have a look at http://www.thinkwiki.org/wiki/HDAPS#Kernel_patch and patch your kernel with the appropriate patch before using hdapsd.

The mainline hdaps module present in Linux kernels does not support all hdaps-enabled ThinkPads, thus it is recommended to use the one provided by tp_smapi. Additionally the tp_smapi version provides an input interface to the data, which stops hdapsd from polling the data itself all the time, saving your battery.