Comment 23 for bug 383001

phdb: I am quite sure that hdparm will not work on a raid array directly, because it is not a physical drive. Your first try seems plausible if /dev/sde was the physical drive. Probably the HPA modification of the live CD was invalid. I never tried raid 10 however.

On my machine a total "cold boot" requires disconnecting the power cable (or switching off the power at the PSU), a plain power off is not enough.