online moving mailbox to a different partition

[Martin Kraus]

hi. I have several hundred gigs of mail messages on a partition and I'd like
to move it to a different partition but copying takes a very long time and I
don't want to have such a long downtime. 
I was wondering if the renamemailbox command moves a whole mailbox to a
different cyrus partition online including the whole mailbox hierarchy?

thanks
Martin