XXX:
XXX: Rationale: `The NetBSD Guide' seems to not contain any paragraphs
XXX: about using USB flash drives in `Chapter 13. Using removable media'.
XXX: The following notes show an example how to initialize and create an
XXX: MS-DOS partition and filesystem on an USB flash drive.
XXX:

USB flash drives can be used to share data among machines.
After attaching it we can see via dmesg(8) that it is recognised
as `sd0':

    # dmesg
    [...]
    sd0 at scsibus0 target 0 lun 0: <Kingston, DataTraveler 3.0, > disk removable
    sd0: fabricating a geometry
    sd0: 14755 MB, 14755 cyl, 64 head, 32 sec, 512 bytes/sect x 30218842 sectors
    sd0: fabricating a geometry
    [...]

WARNING:
WARNING: Please note that the following commands will erase all the previous
WARNING: contents on the USB flash drive!
WARNING:

To initialize it we can write zeros in the first 1MB of the USB flash drive:

   # dd if=/dev/zero of=/dev/rsd0d bs=1m count=1
   1+0 records in
   1+0 records out
   1048576 bytes transferred in 0.118 secs (8886237 bytes/sec)

Via fdisk(8) we can create a partition table. MS-DOS partition and
filesystem is supported by most operating systems and devices that
accept an USB disk, so let's update the partition table (`-u'),
creating an MS-DOS partition and set the new partition as active
(`-a'):

    # fdisk -au sd0
    fdisk: primary partition table invalid, no magic in sector 0
    fdisk: Cannot determine the number of heads
    Disk: /dev/rsd0d
    NetBSD disklabel disk geometry:
    cylinders: 14755, heads: 64, sectors/track: 32 (2048 sectors/cylinder)
    total sectors: 30218842, bytes/sector: 512
    
    BIOS disk geometry:
    cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
    total sectors: 30218842
    
    Partitions aligned to 16065 sector boundaries, offset 63
    
    Do you want to change our idea of what BIOS thinks? [n]
    
    Partition table:
    0: <UNUSED>
    1: <UNUSED>
    2: <UNUSED>
    3: <UNUSED>
    Bootselector disabled.
    No active partition.
    Drive serial number: 0 (0x00000000)
    Which partition do you want to change?: [none] 0
    The data for partition 0 is:
    <UNUSED>
    sysid: [0..255 default: 169] 11
    start: [0..1881cyl default: 63, 0cyl, 0MB]
    size: [0..1881cyl default: 30218779, 1881cyl, 14755MB]
    bootmenu: [] (space to clear)
    
    Partition table:
    0: Primary DOS with 32 bit FAT (sysid 11)
        start 63, size 30218779 (14755 MB, Cyls 0-1881/9/10)
            PBR is not bootable: All bytes are identical (0x00)
    1: <UNUSED>
    2: <UNUSED>
    3: <UNUSED>
    Bootselector disabled.
    No active partition.
    Drive serial number: 0 (0x00000000)
    Which partition do you want to change?: [none]
    Do you want to change the active partition? [n] y
    Choosing 4 will make no partition active.
    active partition: [0..4 default: 4] 0
    Are you happy with this choice? [n] y
    
    We haven't written the MBR back to disk yet.  This is your last chance.
    Partition table:
    0: Primary DOS with 32 bit FAT (sysid 11)
        start 63, size 30218779 (14755 MB, Cyls 0-1881/9/10), Active
            PBR is not bootable: All bytes are identical (0x00)
    1: <UNUSED>
    2: <UNUSED>
    3: <UNUSED>
    Bootselector disabled.
    First active partition: 0
    Drive serial number: 0 (0x00000000)
    Should we write new partition table? [n] y

Then we can see via disklabel(8):

    # disklabel sd0
    # /dev/rsd0d:
    type: SCSI
    disk: DataTraveler 3.0
    label: fictitious
    flags: removable
    bytes/sector: 512
    sectors/track: 32
    tracks/cylinder: 64
    sectors/cylinder: 2048
    cylinders: 14755
    total sectors: 30218842
    rpm: 3600
    interleave: 1
    trackskew: 0
    cylinderskew: 0
    headswitch: 0           # microseconds
    track-to-track seek: 0  # microseconds
    drivedata: 0
    
    5 partitions:
    #        size    offset     fstype [fsize bsize cpg/sgs]
     d:  30218842         0     unused      0     0        # (Cyl.      0 -  14755*)
     e:  30218779        63      MSDOS                     # (Cyl.      0*-  14755*)
    disklabel: boot block size 0
    disklabel: super block size 0

that an sd0e MSDOS partition is present.
We can finally create an MS-DOS filesystem via newfs_msdos(8):

   # newfs_msdos /dev/rsd0e
   /dev/rsd0e: 30189264 sectors in 1886829 FAT32 clusters (8192 bytes/cluster)
   MBR type: 11
   bps=512 spc=16 res=32 nft=2 mid=0xf0 spt=32 hds=64 hid=0 bsec=30218779 bspf=14741 rdcl=2 infs=1 bkbs=2

It is ready to be used and mounted via mount_msdos(8).