Mounting SD card.

[Warren Block]

On Wed, 14 Nov 2012, Mike Clarke wrote:

> On Wednesday 14 November 2012 19:43:30 Fernando Apesteguía wrote:
>
>> If I boot the system and plug the SD card in, the green led
>> doesn't even switch on and there is only a /dev/da0 that I can not
>> mount. If I boot the system with the card plugged in, the green led is
>> on and there is a /dev/da0s1 device that I can't still mount because
>> mount_msdosfs returns an Input/Output error after some time.
>
> I think that's pretty much standard behaviour. The solution appears to be
> to "wake" it up with the following incantation:
>
>     dd if=/dev/null of=/dev/da0 count=0
>
> That's what works here. See the thread starting with
> <http://lists.freebsd.org/pipermail/freebsd-questions/2010-February/212109.html>

true > /dev/da0

is a little shorter and safer.  The search keywords for this are "GEOM 
retaste" or "retasting".