GELI devices produced with 9.0+ fail when mounted on 8.2, etc?

[Garrett Cooper]

On Oct 16, 2011, at 5:32 PM, Xin LI wrote:

> On Sun, Oct 16, 2011 at 5:01 PM, Garrett Cooper <yanegomi at gmail.com> wrote:
> [...]
>>        The attach will fail with the following message:
>> 
>> geli: MD5 hash mismatch for /dev/md0.
> 
> I'm pretty sure that this is from userland, and because FreeBSD 9.x
> have support of GELI metadata version 6, while 8.2 have support up to
> metadata version 5.  It's not a regression IMHO.

In other words this is a design flaw, because geli metadata is only forwards compatible. One of FreeBSD's claims to fame is its backwards compatibility -- why aren't geom developers adhering to this?
Thanks,
-Garrett