source: vendor/current/docs-xml/smbdotconf/logging/logging.xml

<samba:parameter name="logging"
                 type="string"
                 context="G"
                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
<description>

  <para>This parameter configures logging backends. Multiple
    backends can be specified at the same time, with different log
    levels for each backend. The parameter is a list of backends,
    where each backend is specified as backend[:option][@loglevel].</para>

  <para>The 'option' parameter can be used to pass backend-specific
    options.</para>

  <para>The log level for a backend is optional, if it is not set for
    a backend, all messages are sent to this backend. The parameter
    <smbconfoption name="log level"/> determines overall log levels,
    while the log levels specified here define what is sent to the
    individual backends.</para>

  <para>When <smbconfoption name="logging"/> is set, it overrides the
    <smbconfoption  name="syslog"/>  and  <smbconfoption  name="syslog
    only"/> parameters.</para>

  <para>Some backends are only available when Samba has been compiled
  with the additional libraries. The overall list of logging backends:</para>

  <itemizedlist>
    <listitem><para><parameter moreinfo="none">syslog</parameter></para></listitem>
    <listitem><para><parameter moreinfo="none">file</parameter></para></listitem>
    <listitem><para><parameter moreinfo="none">systemd</parameter></para></listitem>
    <listitem><para><parameter moreinfo="none">lttng</parameter></para></listitem>
    <listitem><para><parameter moreinfo="none">gpfs</parameter></para></listitem>
  </itemizedlist>

</description>
<value type="default"></value>
<value type="example">syslog@1 file</value>
</samba:parameter>