In message <19990823185512.B886@antioche.lip6.fr>, Manuel Bouyer writes:
>Hum, error 30 is 'EROFS'. This can happen if you try to write something
>in the space reserved for the disk label I think.

>What does disklabel say for both disks, and your ccd ?

See enclosures.

The summary is, this layout is an attempt to duplicate the effects of
splicing /dev/rwd0c and /dev/rwd1c under BSD/OS; it appears that they skip
the first 32 blocks of each disk.  So, I skip those and ccd the results, and
I've just been using the fictitious geometry.  It appears to work fine apart
from this one error...

# /dev/rwd0c:
type: unknown
disk: Maxtor 90680D4  
label: fictitious
flags:
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 11
sectors/cylinder: 32
cylinders: 415044
total sectors: 13281408
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0		# milliseconds
track-to-track seek: 0	# milliseconds
drivedata: 0 

8 partitions:
#        size   offset     fstype   [fsize bsize   cpg]
  c: 13281408        0     unused        0     0         # (Cyl.    0 - 415043)
  h: 13281376       32     4.2BSD     4096 32768    16   # (Cyl.    1 - 415043)
# /dev/rwd1c:
type: unknown
disk: Maxtor 90680D4  
label: fictitious
flags:
bytes/sector: 512
sectors/track: 32
tracks/cylinder: 11
sectors/cylinder: 32
cylinders: 415044
total sectors: 13281408
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0		# milliseconds
track-to-track seek: 0	# milliseconds
drivedata: 0 

8 partitions:
#        size   offset     fstype   [fsize bsize   cpg]
  c: 13281376       32     unused        0     0         # (Cyl.    1 - 415043)
  h: 13281376       32     4.2BSD     4096 32768    16   # (Cyl.    1 - 415043)
# /dev/rccd0c:
type: ccd
disk: ccd
label: default label
flags:
bytes/sector: 512
sectors/track: 2048
tracks/cylinder: 1
sectors/cylinder: 2048
cylinders: 12970
total sectors: 26562560
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0		# milliseconds
track-to-track seek: 0	# milliseconds
drivedata: 0 

3 partitions:
#        size   offset     fstype   [fsize bsize   cpg]
  c: 26562560        0     4.2BSD        0     0     0   # (Cyl.    0 - 12969)