[Samba] samba 3 to samba 4 migration questions

[Chris Smith]

Here's some of the output I get when attempting said classic upgrade
on a new server:
=========================================================
...
Exporting groups
Ignoring group 'Domain Admins'
S-1-5-21-3233973033-2037430543-4235996074-512 listed but then not
found: Unable to enum
erate group members, (-1073741722,No such group)
Exporting users
Ignoring group memberships of 'FOGHORN$'
S-1-5-21-3233973033-2037430543-4235996074-1006: Unable to enumerate
group mem
berships, (-1073741724,No such user)
Ignoring group memberships of 'visit0r'
S-1-5-21-3233973033-2037430543-4235996074-1007: Unable to enumerate
group memb
erships, (-1073741724,No such user)
...
Importing groups
Group already exists
sid=S-1-5-21-3233973033-2037430543-4235996074-513, groupname=Domain
Users existing_groupname=Doma
in Users, Ignoring.
                                              $
Group already exists
sid=S-1-5-21-3233973033-2037430543-4235996074-512, groupname=Domain
Admins existing_groupname=Dom
ain Admins, Ignoring.
Group already exists
sid=S-1-5-21-3233973033-2037430543-4235996074-514, groupname=Domain
Guests existing_groupname=Dom
ain Guests, Ignoring.
...
(and a bunch of the following)
idmap range not specified for domain '*'
idmap range not specified for domain '*'
=========================================================

In the exporting section groups, users, and machines cannot be
enumerated as either users or groups do not exist. Although in the
importing section groups such as Domain Admins which could not be
previously enumerated in the exporting section are claimed to already
exist and are ignored.

Do the /etc/passwd and /etc/group files on the new server I'm
migrating only the DC duties to need to have the same users and groups
as the old server which will be used for just file and print serving
before starting the upgrade?

Thanks,

Chris