[Samba] passdb.tdb shows no users in new 4.3.11-ubuntu install?

[David H. Durgee]

I enabled logging at level 3 on my new 4.3.11-ubuntu (sylvia) system to 
see why I was not opening a share properly from another system. The log 
shows:

    [2018/06/11 20:49:13.418108,  3]
    ../source3/auth/auth.c:178(auth_check_ntlm_password)
       check_ntlm_password:  Checking password for unmapped user
    [AGI-NET]\[dhdurgee]@[Z560] with the new password interface
    [2018/06/11 20:49:13.418124,  3]
    ../source3/auth/auth.c:181(auth_check_ntlm_password)
       check_ntlm_password:  mapped user is: [DG41TY]\[dhdurgee]@[Z560]
    [2018/06/11 20:49:13.418178,  3]
    ../source3/auth/check_samsec.c:400(check_sam_security)
       check_sam_security: Couldn't find user 'dhdurgee' in passdb.
    [2018/06/11 20:49:13.418201,  2]
    ../source3/auth/auth.c:315(auth_check_ntlm_password)
       check_ntlm_password:  Authentication for user [dhdurgee] ->
    [dhdurgee] FAILED with error NT_STATUS_NO_SUCH_USER
    [2018/06/11 20:49:13.428484,  3]
    ../source3/auth/auth_util.c:1602(do_map_to_guest_server_info)
       No such user dhdurgee [AGI-NET] - using guest account


So it appears that "dhdurgee" is not in passdb for some reason. Checking 
this on that system shows:

    dhdurgee at DG41TY ~ $ sudo pdbedit --list --verbose
    [sudo] password for dhdurgee:
    WARNING: The "syslog" option is deprecated
    dhdurgee at DG41TY ~ $


So there are no users in passdb?  Doing the same on 3.6.25 (maya) shows 
unix users nobody and dhdurgee as expected.

Is the passdb compatible between the two?  Can I simply copy the 3.6.25 
version over the 4.3.11 one?  Shouldn't the passdb have been initialized 
properly when samba was installed?  Is there an initialization utility 
to run to do so? The 3.6.25 version of passdb.tdb is 36864 bytes while 
the 4.3.11 version is 421888 bytes respectively.

Dave