USB mass storage device oddness

Michael McGoldrick michael at
Sat Jul 12 03:02:12 PDT 2003

On Fri, Jul 11, 2003 at 10:22:53PM +0200, Poul-Henning Kamp wrote:
> In message <20030711131218.O8593 at>, Nate Lawson writes:
> >The important part of your error message is "Medium not present".
> >Obviously, when you insert the flash reader into the USB port without any
> >flash media in it, that is the right error to return.  I believe our umass
> >driver and/or your reader do not generate the proper CAM event when the
> >media is inserted.
> >
> >The easy workaround is to always insert the flash in the reader and then
> >the reader into the USB port.
> It may be possible to trigger a reexamination of the device by
> doing a
> 	true > /dev/da0
> (for correct value of 0 obviously)
> -- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk at FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe    
> Never attribute to malice what can adequately be explained by incompetence.

Unfortunately, when I remove a card, the whole umass0 device vanishes, never
to reappear. 
Actually, I can live with removing and reattaching the whole reader every time
I change card, the thing that was really concerning me was the way the system
sometimes 'forgets' how to open any files at all when I remove and reinsert a
card. Sadly, this problem is intermittent and I haven't worked out the
circumstances that trigger it yet. I will update when the whole GCC thing has
blown over and build a debug kernel to see if that sheds any light on the

Michael McGoldrick: mmcgoldrick at 

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