USB can't mount msdosfs drive

[Joseph Mays]

root at warehouse:/backups # mount_msdosfs -o large /dev/da2s1 /usb2
mount_msdosfs: /dev/da2s1: Invalid argument

-----Original Message----- 
From: Warren Block
Sent: Wednesday, June 05, 2013 2:50 PM
To: Joseph Mays
Cc: freebsd-questions at freebsd.org
Subject: Re: USB can't mount msdosfs drive

On Wed, 5 Jun 2013, Joseph Mays wrote:

> Tried several iterations, though it?s clearly a fat32 formatted USB drive. 
> Shown  below are the results of fdisk and the mount_msdosfs command.
>
>
> root at warehouse:/root # fdisk /dev/da2
> ******* Working on device /dev/da2 *******
> parameters extracted from in-core disklabel are:
> cylinders=1897 heads=255 sectors/track=63 (16065 blks/cyl)
>
> Figures below won't work with BIOS for partitions not in cyl 1
> parameters to be used for BIOS calculations are:
> cylinders=1897 heads=255 sectors/track=63 (16065 blks/cyl)
>
> Media sector size is 512
> Warning: BIOS sector numbering starts with sector 1
> Information from DOS bootblock is:
> The data for partition 1 is:
> sysid 12 (0x0c),(DOS or Windows 95 with 32 bit FAT (LBA))
>    start 8064, size 30473088 (14879 Meg), flag 80 (active)
>        beg: cyl 1/ head 0/ sector 1;
>        end: cyl 706/ head 115/ sector 52
> The data for partition 2 is:
> <UNUSED>
> The data for partition 3 is:
> <UNUSED>
> The data for partition 4 is:
> <UNUSED>
>
> root at warehouse:/root # mount_msdosfs /dev/da2s1 /usb2
> mount_msdosfs: /dev/da2s1: Invalid argument
> root at warehouse:/root #

Maybe the "large" option to mount_msdosfs(8)?

Also, something is odd about the first partition starting at 8064.
What does 'gpart show da2' say?