Your harddisk shouldn’t spin-down/spin-up and/or park/unpark too much causing the mechanics of the harddrive to slowly detiorate. If this is happening you should see your Load_Cycle_Count increasing too fast.

The following things might cause aggressive power management :

• your (laptop) harddrive firmware might have aggressive power management defaults (operating system independent)
• your (laptop) BIOS might set your harddrive to use aggressive power management (operating system independent)
• you might have enabled laptop-mode in /etc/default/acpi-support (disabled by default) which will set your harddrive to use aggressive power management

There’s another part of this problem (one of the following might be true) :