Analysis of information sources in references of the Wikipedia article "Western Digital" in English language version.
If linux tends to write to /var/log/* every 30s, then the heads can park/unpark every 30s.
Get/set the Western Digital (WD) Green Drive's "idle3" timeout value. This timeout controls how often the drive parks its heads and enters a low power consumption state. The factory default is eight seconds, which is a very poor choice for use with Linux. Leaving it at the default will result in hundreds of thousands of head load/unload cycles in a very short period of time.
