A few questions:
1.  What do the flags really mean?  I see no documentation of what happens
if you don't specify "uniform interleave".
2.  I'm migrating a BSD/OS "splice" to a NetBSD "ccd" (mostly for hack value).

BSD/OS said:

---
# sp0:
type: Pseudo disk
disk:
label:
flags: logical-geometry
bytes/sector: 512
sectors/track: 2048
tracks/cylinder: 1
sectors/cylinder: 2048
cylinders: 12970
sectors/unit: 26562560
replacement sectors/track: 0
replacement sectors/cylinder: 0
alternate cylinders: 0
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: 26562560        0    4.2BSD     4096 32768    16   # (Cyl.    0 - 12969)
---

NetBSD says:

---
# /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)
disklabel: boot block size 0
disklabel: super block size 0
---

It sure looks to me like they ought to be agreeing, except for the "logical
geometry" issue.

Any suggestions as to how to interpret this?  Also, am I correct in assuming
that ileave is measured in 512-byte blocks?

-s