How can SATA power management feature be controlled?

[Robert Nichols]

How can I control the automatic power management feature of my SATA disk
drives?  Right now the heads are unloading so frequently that within
one year I will have exceeded the rated number of load/unload cycles for
the drives.  The drives are Western Digital model WD10EADS.  I tried
using "hdparm -B 254" and "hdparm -B 0", but neither works:

    # hdparm -B 254 /dev/sda

    /dev/sda:
    setting Advanced Power Management level to 0xfe (254)
    HDIO_DRIVE_CMD failed: Input/output error
    HDIO_DRIVE_CMD(identify) failed: Input/output error
    # hdparm -B 0 /dev/sda

    /dev/sda:
    setting Advanced Power Management level to 0xfe (254)
    HDIO_DRIVE_CMD failed: Input/output error
    HDIO_DRIVE_CMD(identify) failed: Input/output error

My efforts to find anything useful with 'sdparm' have been fruitless.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.