Jason Thorpe wrote:
> 
>  > #        size   offset    fstype   [fsize bsize   cpg]
>  >   a:   638946      414    4.2BSD     1024  8192    16
>  >   c:   639630        0   unknown
>  >
>  > They ccdconfig together just fine, but when I go to edit the
>  > disklabel on the ccd ('disklabel -e ccd0') and then save, I
>  > get :
>  >
>  > disklabel: ioctl DIOCWDINFO: Read-only file system
> 
> Are you using the "a" partition of the component disks?  Hmm.. If you'e
> getting EROFS, it's likely that one of your components falls on the
> label area of a component disk... the label area is protected from writing
> during normal operation.

Yes, I'm using the 'a' partitions (that's why they're there 8).  As
they're
200K away from the start of the disk, I have trouble understanding why
they
would overlay the label.

> Can you send me the output of "ccdconfig -g"?

ccd0            46      0       /dev/sd2a /dev/sd3a /dev/sd4a

All three disks are labelled identically :

# /dev/rsd2c:
type: unknown
disk: CDC Wren IV 941
label: 
flags:
bytes/sector: 512
sectors/track: 46
tracks/cylinder: 9
sectors/cylinder: 414
cylinders: 1545
total sectors: 639630
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]
  a:   638946      414    4.2BSD     1024  8192    16   # (Cyl.    1 -
1544*)
  c:   639630        0   unknown                        # (Cyl.    0 -
1544)

> Jason R. Thorpe                                       thorpej@nas.nasa.gov

--
Mike Smith  *BSD hack  Unix hardware collector
The question "why are the fundamental laws of nature mathematical"
invites the trivial response "because we define as fundamental those
laws which are mathematical".  Paul Davies, _The_Mind_of_God_