Does anybody know how to power off the individual usb ports? Like on windows. I would like to power on / off usb mounted disks.

Well, I don't have anything that I can test with at the moment, but it looks to me that if you find your device with

lsusb -v | less

You should be able to power it off with:

echo "0" > /sys/bus/usb/devices/device/power/state

For example:

echo "0" > /sys/bus/usb/devices/6-0:1.0/power/state

Why don't you try it and let us know?

$:/sys/bus/usb/devices/6-1/power$ echo "0" > /sys/bus/usb/devices/6-0:1.0/power/state
bash: /sys/bus/usb/devices/6-0:1.0/power/state: Permission denied

Even with all combinations of sudo. It seems this attribute is read only, I have not seen this "permission denied" anywhere else.
Discussion continues in other thread, the one I started.
http://www.linuxquestions.org/questi....php?p=2565927
Edit-Clarification
I am not the original poster, and I was trying to use these commands to do something slightly different- power down usb ports, that have various peripherals attached. This turned out to be impossible to do.

Couldn't you just use hdparm to power down the disks?

You may have to do "echo -n 0 > file" instead of "echo 0 > file".

Cheers,
-jon