USB SD-card reader recognized, but not working, on 6.1

[perryh at pluto.rain.com]

Polytropon <freebsd at edvax.de> wrote:
> On Thu, 09 Apr 2009 12:47:23 -0700, perryh at pluto.rain.com wrote:
> > It's an SD card, not a "drive", so I had not expected it to be
> > partitioned; but yes, it is:
> > 
> > $ ls -l /dev/da0*
> > crw-r-----  1 root  operator    0, 244 Feb 14 15:09 /dev/da0
> > crw-r-----  1 root  operator    0, 245 Feb 14 15:09 /dev/da0s1
>
> Why don't you expect this? As far as I know, if something is
> msdosfs-formatted (read: any "Windows" readable file system,
> FAT), it always involves a "slice device". I never found a
> situation where access to /dev/da0 would work.

My experience is exactly the reverse.  I've never before seen a
removable-media device (floppy, Zip-drive, JAZ drive) that *did*
have a DOS "partition" table aka BSD "slice" table.  Surely you
would not expect a USB floppy to show up as /dev/da0s1?

AFAIK the reason for creating slices is to identify sections of
the device for use by different OS -- something often needed
for multi-boot from a hard drive but seldom on removable media.
I sure wasn't planning to use part of this SD card for my camera
to store pictures on, and the rest for FreeBSD backups :)