update..

roles/common/templates/etc/samba/smb.conf.j2

@@ -44,6 +44,22 @@
 ;   netbios name = FILE
    netbios name = {{ samba_netbios_name|default('FILE') }}
 
+{% if samba_server_min_protocol is defined and samba_server_min_protocol|length > 0 %}
+
+# This setting controls the minimum protocol version that the server will allow 
+# the client to use. Normally this option should not be set as the automatic 
+# negotiation phase in the SMB protocol takes care of choosing the appropriate 
+# protocol unless you have legacy clients which are SMB1 capable only.
+#
+# See Related command: server max protocol for a full list of available protocols.
+#
+#   Default: server min protocol = SMB2_02
+#
+#   Example: server min protocol = NT1
+#
+   server min protocol = {{ samba_server_min_protocol }}
+
+{% endif %}
 
 #### Networking ####