zfs upgrade "gpart: /dev/da4p1: not enough space"

[Ian Smith]

In freebsd-questions Digest, Vol 661, Issue 7, Message: 5
On Sat, 4 Feb 2017 20:55:09 -0700 "Russell L. Carter" <rcarter at pinyon.org> wrote:
 > Greetings,
 > 
 > amd64 11/stable
 > 
 > So I'm on the last machine of a zpool upgrade everybody, and on the
 > very last, and most important pool, I zpool upgraded and then
 > went to finish the boot zpool and what did I see:
 > 
 > root at terpsichore> gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1  da3
 > gpart: /dev/da3p1: not enough space
 > 
 > So... what do I do now?  It's happy staying up for days, but... will
 > I have to reinstall the system to make da3p1 big enough?

Saw your follow-up in the archives, but that digest hasn't arrived yet.

I know nothing about this, but have seen similar issues discussed and 
resolved on freebsd-stable@ recently, so suggest trying there.

cheers, Ian