Does anybody use by a chance external SMB storage in current ownCloud version?

If yes, does it work for you?

I have, otherwise fully OK Samba, but my ownCloud cannot get to it. On my setup (pretty default) users log into ownCloud with an ldap backend, the very same Samba uses, yet in Samba logs I see:

….
2017/10/05 15:41:00.479585,  5]
…/source3/auth/server_info_sam.c:122(make_server_info_sam)
make_server_info_sam: made server info for user cloudadmin -> cloudadmin
[2017/10/05 15:41:00.479709,  3]
…/source3/auth/auth.c:249(auth_check_ntlm_password)
check_ntlm_password: sam authentication for user
[cloudadmin] succeeded
[2017/10/05 15:41:00.479772,  5]
…/source3/auth/auth.c:292(auth_check_ntlm_password)
check_ntlm_password:  PAM Account for user [cloudadmin]
succeeded
[2017/10/05 15:41:00.479810,  2]
…/source3/auth/auth.c:305(auth_check_ntlm_password)
check_ntlm_password:  authentication for user
[cloudadmin] -> [cloudadmin] -> [cloudadmin] succeeded
[2017/10/05 15:41:00.481148,  2]
…/source3/passdb/pdb_ldap.c:2310(init_group_from_ldap)
init_group_from_ldap: Entry found for group: 544
[2017/10/05 15:41:00.481740,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-5-32-545))
[2017/10/05 15:41:00.482335,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-5-32-545))
[2017/10/05 15:41:00.484920,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-1-0))
[2017/10/05 15:41:00.485371,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-1-0))
[2017/10/05 15:41:00.485723,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-5-2))
[2017/10/05 15:41:00.486136,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-5-2))
[2017/10/05 15:41:00.486525,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-5-11))
[2017/10/05 15:41:00.486979,  4]
…/source3/passdb/pdb_ldap.c:2437(ldapsam_getgroup)
ldapsam_getgroup: Did not find group, filter was
(&(objectClass=sambaGroupMapping)(sambaSID=S-1-5-11))