What is thinkpad active protection system

The maximum value of invert is obviously 7. If you do not know which option is correct for you, just try them out with hdaps-gl or some other GUI see below. Alternatively, you can determine the exact value for your thinkpad model from this table under the column labelled "HDAPS axis orientation".

Now that your hardware is reporting its shock detection to the OS, we need to do something with this data. This section describes software utilities to transform the sensor output into shock protection. You should check your "Load cycle count" in SMART when setting up hdaps, if it is too sensitive the head would park too often and load cycle count would rise too rapidly. Install hdapsd. You can start hdapsd with hdapsd device. The package installs udev rules.

Udev will start one hdapsd instance for each rotational, non-removable disk it finds. For more information, see the hdapsd github page. It may be desirable to tweak the parameters used by hdaspd. Edit hdapsd. Utilities exist to monitor hdapsd's status so you know what is going on while you are using your laptop. These are entirely optional. Similar to the apllication Lenovo distributes with Windows.

Related articles hpfall. The hardware sensor is capable of not only recognizing acceleration of the notebook, but also to a certain degree of its whole orientation in space, relative to gravity's axis.

Furthermore, having the actual control put into software, its functionality is extendable and it gives chance to implement features like the "ignore minor shocks" feature which is present in the Windows based control applet.

This feature prevents the harddrive from parking in case of minor regular shocks such as occur when in a train or car. The measurements are physically performed by an Analog Devices ADXL accelerometer chip, managed by the embedded controller. HD-APS requires a hard-disk with head unload ramp technology and also support on the hard-disk firmware to unload heads without flushing the disk cache.

This is required, because as soon as the APS system detects a shock is imminent, the system has less than ms to prepare for the shock. It finishes whatever sector write is in-flight, and immediately moves the heads to the unload ramp. Without this command, hard-disk APS cannot be trusted, as disks with big caches can take a lot of time to write it all to disk.

Head unload technology is reasonably common in modern laptop disks, but the APS firmware is very rare in regular consumer products. Please note that newer Apple notebooks also support APS, so it is somewhat likely that their disks also support unload immediate or a similar feature.

Update: February, Meanwhile, other HDD manufacturers may have added the necessary support to their new products.

The description reads pretty much like what's needed for APS, though I don't want to drop my almost new TP just to field-test it. This feature definitely depends on software and there is no hardware or BIOS-only way of making it work. IBM made contradictory statements about their willingness to release the specifications of the hardware sensor and its API to the linux community or some developers.

Although a lot of developers and other interested people from the OpenSource community actively contacted IBM to get the specs, in fact they never got them. Later, a kernel patch to enable harddisk parking followed. Furthermore, a list of alternative applications like theft alarm and others can be found on the HDAPS driver page.