[Gllug] Backup drive for CentOS 5 remote setup

[Frank Scott]

On Tue, Aug 17, 2010 at 08:50:24AM -0400, Andrew Farnsworth wrote:
> Power to the USB drive is limited by the USB standard to 500 mw or 1/2 a
> watt.  If you are using a short chunky cable as opposed to a long thin one,
> I would suspect the long thin one doesn't actually have the power wires and
> is really just a 2 wire cable... not really a USB cable at all.  You could
> check this with a multimeter pretty easily or try the same cable with
> another USB powered device that uses less power.
> 
> If you are running the drive off a server, you should not have to worry
> about USB power as each port should supply up to 500 mw.  if you are
> connecting these devices to a laptop that is not plugged in... then I would
> worry.  Or if you were plugging them into an unpowered USB hub.  A powered
> USB hub should supply 500 mw to each port... well the good ones anyway.
> 

s/500 mw/500 mA/ or more strictly a high powered USB2.0 device can draw up to 5
100mA load units at 5.0+/- 0.25 V.

fcs
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