Subject: Re: ccd, disklabel
To: Jens A Nilsson <>
From: Tom T. Thai <>
List: port-i386
Date: 11/02/1998 13:09:34
On Mon, 2 Nov 1998, Jens A Nilsson wrote:
> The problem is that you need an offset for the partitions you ccd.
> Look at ccd(4), it's described in the beginning of the manpage.

man ccd:
     Note that the `raw' partitions of the disks should not be combined.
     Each component partition should be offset at least one cylinder from
     the beginning of the component disk.  This avoids potential conflicts
     between the component disk's disklabel and the ccd's disklabel.  The
     kernel will only allow component partitions of type FS_BSDFFS.

given that all my disks are laid out the same per disklabel below for each
#        size   offset    fstype   [fsize bsize   cpg]
a:   224700        0      4.2BSD     1024  8192    16   # (Cyl.    0-99)
b:   224700   224700        swap                        # (Cyl.  100-199)
c:  8340864        0      unused        0     0         # (Cyl.    0-3711)
d:  8340864        0      unused        0     0         # (Cyl.    0-3711)
e:  7891464   449400      4.2BSD     1024  8192    16   # (Cyl.  200-3711)

so if I want to ccd each partition of each disk sdXa into ccd1, then I
have to offset partition a from the original disklabel?  i.e. partition a
above (for each sdx) should be:

a:   224700        1      4.2BSD     1024  8192    16   # (Cyl.    0-99)
                  --- <-- changed from 0 to 1

what about partition e for each disk?  should that be offset by one too?
i have ccd0 using all the partitions sdXe right now with out that offset.

oh a side note, where is the disklabel for a ccd really written?