I need to add two more swap partitions, but swapon reports "device not
configured."  I used mkfs_1.4 to convert a pair of 10M HFS partitions to
swap, but no dice.  I even tried letting it format one of them.  They
are on the same device as / and the regular swap partition.  Is there
something to format/configure swap that i've forgotton about?  here is
the disk information if it helps:

hawkins# disklabel sd0
# /dev/rsd0c:
type: SCSI
disk: SCSI disk
label: fictitious
flags:
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 6
sectors/cylinder: 192
cylinders: 834
total sectors: 164058
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # milliseconds
track-to-track seek: 0  # milliseconds
drivedata: 0 

7 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  a:    40963    82135    4.2BSD        0     0     0   # (Cyl.  427*- 641*)
  b:    20491    61644      swap                        # (Cyl.  321*- 427*)
  c:   164058        0    unused        0     0         # (Cyl.    0 - 854*)
  d:       32       64   unknown                        # (Cyl.    0*- 0*)
  e:    40140       96       HFS                        # (Cyl.    0*- 209*)
  f:    21408    40236      swap                        # (Cyl.  209*- 321*)
  g:    40960   123098      swap                        # (Cyl.  641*- 854*)
disklabel: boot block size 0
disklabel: super block size 0