Reattach/redetect allways connected umass device - is it possible ?

[Bernd Walter]

On Mon, Mar 28, 2005 at 02:13:16PM +0200, Poul-Henning Kamp wrote:
> In message <20050328114633.GZ14532 at cicely12.cicely.de>, Bernd Walter writes:
> 
> >> camcontrol detach da0; camcontrol rescan all 
> >> helps, but, it should be much better if it will be issued automatically.
> >
> >Yes - GEOM seems to ignore media change signals from drives.
> >I've added PHK to the recipient list - maybe he has an idea about this
> >problem.
> 
> No, GEOM doesn't ignore any such thing, because as far as I know
> GEOM doesn't get any such thing to ignore in the first place.

At least with (most) SCSI devices you get a media changed exception
on the first access after that.
Don't know if you see them under GEOM, but the kernel prints it:
Mar 28 15:09:21 cicely13 kernel: (da0:ahc0:0:1:0): READ CAPACITY. CDB: 25 0 0 0 0 0 0 0 0 0 
Mar 28 15:09:21 cicely13 kernel: (da0:ahc0:0:1:0): CAM Status: SCSI Status Error
Mar 28 15:09:21 cicely13 kernel: (da0:ahc0:0:1:0): SCSI Status: Check Condition
Mar 28 15:09:21 cicely13 kernel: (da0:ahc0:0:1:0): UNIT ATTENTION asc:28,0
Mar 28 15:09:21 cicely13 kernel: (da0:ahc0:0:1:0): Not ready to ready change, medium may have changed
Mar 28 15:09:21 cicely13 kernel: (da0:ahc0:0:1:0): Retrying Command (per Sense Data)
This was introduced with cp /dev/null /dev/da0, but happens on every
possible access.
As I said - many cheap devices are to stupid for this, but at least
it's defined for SCSI and quality devices usually support it.
This is true for all kind of removeable device types, da, cd, sa, ...

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de