vnconfig and a compact flash disk image

[Warren Block]

On Fri, 20 Aug 2004, Richard P. Williamson wrote:

> At 14:49 20/08/2004. Warren Block had this to say:

>> See the example of how to mount an ISO CD image in the examples 
>> section of the vnconfig man page; it should be the same, except the 
>> filesystem type will be msdos.

> msdos?  Ok, that confuses me.  The flash card isn't msdos
> compatible (or shouldn't be). According to fdisk, it is 165,
> which is the way it was created:

Sorry, I missed that.  Flash cards are almost always FAT formatted.

> venus# vnconfig vn0 san32.img

I don't know what that does, but it does not agree with the examples in 
the vnconfig man page.  Instead, it should be

vnconfig -c -v /dev/vn0 san32.img

(It may also need the -s labels option.)

Then you can mount it:

mount /dev/vn0 /mnt

> The output is the same regardless if it is an image created by
> dd'ing /dev/ad8 or /dev/rad8 (which is how I'm getting the
> "san32.img" off the flash card in the first place).
>
> The 'can't get disk parameters' worries me.  Does
> dd if=/dev/rad8 of=san32.img
> not do what I think?

Possibly not.  I've only seen the "r" prefix for tape drives, meaning 
"rewind after use".  As shown, I think it would copy every block of the 
card, the same as /dev/ad8.

If the card has a partition table, you should be able to dd the 
individual slices:

dd if=/dev/ad8s1 of=san32slice1.img
dd if=/dev/ad8s2 of=san32slice2.img

-Warren Block * Rapid City, South Dakota USA