help setting up encrypted partition

[scar <scar%drigon.com@localhost>]

i am trying to setup an encrypted partition on my disk by following the
guide[1] but i am a bit lost and not quite understanding the way NetBSD
partitions disks

/dev/wd1 is the disk i want to use (entirely) and it has been zeroed out
with dd but i guess needs to be labeled and partitioned first before i
can proceed to section " 14.3.2. Scrubbing the disk "?  i was able to
enter this command:
# cgdconfig -s cgd0 /dev/wd1e aes-cbc 128 < /dev/urandom

but when i try the next command this happens:
# dd if=/dev/zero of=/dev/rcgd0c bs=32k
dd: /dev/rcgd0c: Read-only file system

(note that i'm not using NetBSD/i386 (but sparc64) so that's why i
changed it to rcgd0c)
is wd1e even the right partition i want to use?  wouldn't i want wd1c so
i can use the whole disk?  but when i try that with the cgdconfig i get
"Operation not supported by device"

if i try to use 'disklabel -i /dev/wd1' i get a "could not read existing
label" error, and here[2] is the output of fdisk.

so anyway i guess if could get a little more help preparing the disk so
i can get the encrypted partition setup, would appreciate it!


1. http://www.netbsd.org/docs/guide/en/chap-cgd.html#chap-cgd-example
2. http://pastebin.com/LnEBDBfW