zpool creation on geli failed with FreeBSD-9.0

[Christopher J. Ruwe]

I was trying to install FreeBSD 9.0 using a geli encrypted disk and
ZFS on my ThinkPad R500 this weekend. I failed. 

Having sucessfully initialized the geli part and having attached the
provider, my attempt to create a zpool on the geli section thus

$> zpool create ntank /dev/ada0p2.eli 

failed with the message 

Cannot create 'ntank': invalid argument for this pool operation.

I could not convince the system to create the zpool on the geli part, so
I gave up and created the zpool on the unencrypted partition instead to
have a working machine for the week. I would, however, like to have my
data on an encrypted partition though. Has anyone witnessed and resolved
this issue or does anyone have other ideas?

Thanks for your help, cheers,
--
Christopher J. Ruwe
TZ GMT + 2h