USB device activity when not mounted

Mike Clarke jmc-freebsd2 at
Thu Jun 14 15:18:55 UTC 2012

On Thursday 14 June 2012 15:45:46 Polytropon wrote:

> However, as you said
> it might be possible that _inside_ the USB stick there is
> still an action that needs to be performed and therefore
> requires power.

That's a possibility.

> But I doubt this takes several seconds to 
> complete...

I've just run a test here. The umount command returns almost instantaneously  
and the light, which is normally only lit while data is flowing,  flickers 
for about 2 seconds after the umount command. But further testing showed that 
it flickers for 2 seconds after reading  single byte file so perhaps the 
blinkenlight is configured with a minimum activation time.

Being cautious however, I always wait a few seconds before removing any USB 
stick from any computer.

Mike Clarke

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