[Samba] upgrade 4.0.6 to 4.3.8

[Mike Ray]

Hello samba users-

I've got a long overdue update to my domain controllers. Currently my domain controllers are running samba 4.0.6 on Ubuntu 12.04. I would like to upgrade to 4.3.8. 

I've read through the update page (https://wiki.samba.org/index.php/Updating_Samba) and it seems to be pretty straightforward.

Are there any other suggestions, particularly from users who have done a similar upgrade (i.e. a big jump in version)?

Thanks,

Mike Ray