[Samba] Migrate DCs on ubuntu 14.04 to ubuntu 18.04

[Emilian Mitocariu]

Hi,

I'm having the following setup: 3 offices, with at least 2 DCs per office.
Every DC is running on ubuntu 14.04 with either samba 4.3.9 or 4.3.11. I'm
not the one that build these DCs but from documentation and what I'm told,
nothing fancy was done on them, just joined the domain, added
users/fileservers and group policy replication as described here:
https://wiki.samba.org/index.php/Rsync_based_SysVol_replication_workaround

I have to upgrade/migrate these DCs, so my strategy is to build new DCs on
ubuntu 18.04, which comes with samba 4.7.6, join these new DCs to the
domain, move the FSMO roles to one of the new DCs, move the group policy
replication to new DCs as well and remove the old DCs from domain.

My question is, will all data replicate from old DCs to new DCs alright,
considering the difference between samba versions?