Kaha persistence size

[Eugene Prokopiev]

Hi,

I use Kaha Persistence with this configuration:
<beans xmlns="http://activemq.org/config/1.0";>

    <broker useJmx="true" persistent="false" populateJMSXUserID="true">

        <transportConnectors>
            <transportConnector name="default" 
uri="tcp://localhost:61616"/>
        </transportConnectors>

        <persistenceAdapter>
            <kahaPersistentAdaptor dir = "../activemq-data"/>
        </persistenceAdapter>

    </broker>

</beans>

Then I send 10 000 text messages I see that ../activemq-data increased 
at 6Mb but I can't see it's decreasing on recieving messages. Why is it? 
What will be happen after sending 10 000 000 messages?

--
Thanks,
Eugene Prokopiev