Эксперимент такой (все делается по man raidctl):

Есть: sd1, sd2, sd3 + пересобранное ядро с нужными опциями.

все диски разбиты однотипно:

# fdisk /dev/rsd0c
Disk: /dev/rsd0c        geometry: 1106/255/63 [17767890 Sectors]
Offset: 0       Signature: 0xAA55
         Starting       Ending       LBA Info:
#: id    C   H  S -    C   H  S [       start:      size   ]
------------------------------------------------------------------------
0: A6    0   1  1 - 1105 254 63 [          63:    17767827 ] OpenBSD
1: 00    0   0  0 -    0   0  0 [           0:           0 ] unused
2: 00    0   0  0 -    0   0  0 [           0:           0 ] unused
3: 00    0   0  0 -    0   0  0 [           0:           0 ] unused

# disklabel /dev/sd0c
# using MBR partition 0: type A6 off 63 (0x3f) size 17767827 (0x10f1d93)
# /dev/sd0c:
type: SCSI
disk: SCSI disk
label: ST19171W
flags:
bytes/sector: 512
sectors/track: 168
tracks/cylinder: 20
sectors/cylinder: 3360
cylinders: 5268
total sectors: 17783112
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0

16 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  c: 17783112        0    unused        0     0         # (Cyl.    0 -5292*)
  f:   100000       63      RAID                        # (Cyl.    0*- 29*)
#

# cat raid0.conf
START array
# numRow numCol numSpare
1 2 1
START disks
/dev/sd1f
/dev/sd2f
START layout
# sectPerSU SUsPerParityUnit SUsPerReconUnit RAID_level_1
128 1 1 1
START queue
fifo 100
START spare
/dev/sd0f

инициализируем по книжке.... -C ... -I 100 ... -i ...

# raidctl -f /dev/sd1f raid0
# raidctl -s raid0
raid0 Components:
           /dev/sd1f: optimal
           /dev/sd2f: failed
Spares:
           /dev/sd0f: spare
Parity status: clean
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.

# raidctl -F /dev/sd1f raid0
# raidctl -s raid0
raid0 Components:
           /dev/sd1f: optimal
           /dev/sd2f: spared
Spares:
           /dev/sd0f: used_spare
Parity status: clean
Reconstruction is 100% complete.
Parity Re-write is 100% complete.
Copyback is 100% complete.

Потом книжка советует raidctl -B ....

Ядро паникует (... LK_RELEASE ....)

Где грабли?

• Software RAID under OpenBSD, stalker, 23:12 , 18-Ноя-03, (1)