$ rmformat -F quick /dev/rdiskette
Formatting will erase all the data on disk.
Do you want to continue? (y/n)y
$ su
# newfs /dev/rdiskette
newfs: construct a new file system /dev/rdiskette: (y/n)? y
/dev/rdiskette: 2880 sectors in 80 cylinders of 2 tracks, 18 sectors
        1.4MB in 5 cyl groups (16 c/g, 0.28MB/g, 128 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
 32, 640, 1184, 1792, 2336,
#