Can not mount USB device

[Bernt Hansson]

On 2016-10-17 22:25, doug wrote:
> The system is FreeBSD 10.3-RELEASE-p7 #0. All commands are execured as 
> root.
>
> file -s /dev/da0s1
> /dev/da0s1: DOS/MBR boot sector, code offset 0x58+2, OEM-ID 
> "MSDOS5.0", sectors/cluster 8, reserved sectors 38, Media descriptor 
> 0xf8, sectors/track 63, heads 16, hidden sectors 8192, sectors 831488 
> (volumes > 32 MB) , FAT (32 bit), sectors/FAT 813, serial number 
> 0x482393a9, unlabeled
>
> I ended up with the following attempts
>
> mount -t msdosfs -o -m=644 /dev/da0s1 /mnt/
> 5mount_msdosfs: /dev/da0s1: Permission denied
>
> dmesg:
> (da0:umass-sim0:0:0:0): Error 13, Unretryable error
> g_vfs_done():da0s1[WRITE(offset=19456, length=4096)]error = 13
> (da0:umass-sim0:0:0:0): WRITE(10). CDB: 2a 00 00 00 20 26 00 00 08 00
> (da0:umass-sim0:0:0:0): CAM status: SCSI Status Error
> (da0:umass-sim0:0:0:0): SCSI status: Check Condition
> (da0:umass-sim0:0:0:0): SCSI sense: DATA PROTECT asc:27,0 (Write 
> protected)
>
> mount -t msdosfs -o -m=644,-M=644 /dev/da0s1 /mnt/
> mount_msdosfs: /dev/da0s1: Permission denied
>
> dmesg:
> (da0:umass-sim0:0:0:0): Error 13, Unretryable error
> g_vfs_done():da0s1[WRITE(offset=19456, length=4096)]error = 13
>
> All other variations got the same error (Permission denied)
>
> The USB stick is readable in windows 10. I thought it was a data disk 
> it turns out to have 2 install program files one for windows and one 
> for mac.
Is the filesystem clean?

Try running fsck.