I am having trouble mounting a partition on a bootable USB drive.

[Omphalotus_japonicus]

I have a USB drive with the OpenBSD 6.8 installation medium flashed onto it along with one other fat16 formatted partition which has a piece of firmware on it. Despite my best attempts, I've not yet been able to mount this partition despite me knowing the label for it (sd2j in my case); it results in the error "mount ffs: /dev/sd2j on /mnt: Device not configured" every time I've tried as if it doesn't exist.

My one and only clue might be that doing the command "disklabel sd2" only shows the flashed installation medium partitions of the USB drive and not my other partition with the piece of firmware on it; the only way I can get my other partition to display is if I use the "-d" argument in the command.

[jggimi]

Hello, and welcome!

If a disk drive already has a disklabel on disk, the OS will not scan an MBR or GPT partition table to look for any foreign filesystems. You will need to edit the disklabel to add your additional filesystem manually. The fdisk(8) command can be used to determine starting sector (LBA) and length of the new partition, and those values can be added interactively with the disklabel(8) command's built-in editor (# disklabel -E sd2). Add the FAT filesystem as type "msdos" in the built-in editor when prompted for the filesystem type.