ATAidle sets the idle timer on ATA hard drives, so they spin down when the 
period of inactivity has expired.  To use it, you must be running FreeBSD 6.2 
or newer - alternatively, you can also
run it on Linux - it's been tested with kernel 2.6.1, but should work with
any recent kernel.

Supplying a device name without any parameters will display 
information about the specified device.

Notes on Auto Acoustic Management (AAM) and APM support

Use of this feature is experimental, and may crash your computer - although
it is believed to be stable, it is modifying hard disk behaviour as data is
being read or written, so any fault in the drive could have disastrous
consequenses for your data.

Meaning of various AutoAcoustic values:

0		Acoustic management disabled
1		Minimum acoustic output
2-126		Intermediate acoustic output levels
127		Maximum performance, maximum acoustic output

Meaning of various APM values:

1		Minimum power usage with Standby (spindown)
2-127		Intermediate power usage with Standby
128		Minimum power usage without Standby (no spindown)
129-253		Intermediate power usage without Standby
254		Maximum performance, maximum power usage

Some values may not be supported, in this case you will see an error
message 'Set APM failed: Inappropriate ioctl for device'.