B<address> means use the interface's mac address. This is useful since the
interface path might change between reboots of a guest or across migrations.
-=item B<PluginInstanceFormat> B<name|uuid>
+=item B<PluginInstanceFormat> B<name|uuid|none>
When the virt plugin logs data, it sets the plugin_instance of the collected
-data according to this setting. The default is to use the guest name as provided
-by the hypervisor, which is equal to setting B<name>.
+data according to this setting. The default is to not set the plugin_instance.
+B<name> means use the guest's name as provided by the hypervisor.
B<uuid> means use the guest's UUID.
+You can also specify combinations of the B<name> and B<uuid> fields.
+For example B<name uuid> means to concatenate the guest name and UUID
+(with a literal colon character between, thus I<"foo:1234-1234-1234-1234">).
+
=back
=head2 Plugin C<vmem>
=item B<AlwaysAppendDS> B<false>|B<true>
-If set the B<true>, append the name of the I<Data Source> (DS) to the
+If set to B<true>, append the name of the I<Data Source> (DS) to the
"service", i.e. the field that, together with the "host" field, uniquely
identifies a metric in I<Riemann>. If set to B<false> (the default), this is
only done when there is more than one DS.