Problem with 16-in-1 card reader

[Simon Dick]

...... Original Message .......
On Sat, 11 Mar 2006 16:24:21 -0700 (MST) "M. Warner Losh" <imp at bsdimp.com> 
wrote:
>In message: <20060311124931.62eee647 at frankie.konav201.local>
>            Robert Marella <rmarella at gmail.com> writes:
>: On Sat, 11 Mar 2006 13:51:30 +0100
>: Alex Dupre <ale at FreeBSD.org> wrote:
>: 
>: > My new PC has an internal 16-in-1 card reader connected via USB 2.0.
>: > The device is the Techsolo TCR-1640
>: > (http://www.techsolo.de/product/cardreader/tcr_1640/index.php).
>: > I boot from a compact flash inserted in it and I can mount and unmount
>: > the same CF once the system has booted and has mounted the root
>: > partition from my graid3 array.
>: > The problem arise when I replace the inserted CF with another one
>: > (with different size and filesystem) and try to mount it. Fdisk can
>: > correctly sees the new partition table, but devfs is not updated and
>: > I cannot mount the new media. 
>: 
>: <snip>
>: 
>: Hello Alex
>: 
>: This problem has been discussed many times on the lists. In order to
>: update devfs you can use:
>: 
>: cat /dev/null > /dev/daX
>: 
>: I seem to remember another method using dd.
>
>dd if=/dev/null of=/dev/daX count=0

true >/dev/daX
is my favourite due to typing length.