solaris to freebsd ZFS version

[krad]

Hi,

I'm currently porting a large zfs data set from a solaris host to a freebsd
one. I knew this was always a possibility so it made sure the pool versions
were 28. I however forgot about the dataset version. Downgrading from v6 to
v5 was fairly easy in the end it just took a long time. However im not able
to do this for the root dataset, as i cant rename it. It has no data on it
so its more of a loose end and anoyance than anything else, and I dont
think its going to be a massive issue for me but it would be good to fix if
i can. Has anyone had any luck doing this other than rebuilding the pool
which  I dont want to have to do as this would be difficult due to the size.