This is set in the Guvnor beans.xml file, specifically:
<!-- JackRabbit -->
<guvnorRepository:properties>
<s:entry><s:key>org.drools.repository.configurator</s:key><s:value>org.drools.repository.jackrabbit.JackrabbitRepositoryConfigurator</s:value></s:entry>
<!-- the root directory for the repo storage the directory must exist. -->
<!--<s:entry><s:key>repository.root.directory</s:key><s:value>/opt/yourpath</s:value></s:entry>-->
</guvnorRepository:properties>
By default the repository directory is created in the same directory where you start the server. If you use the installer it will be created in $installer/repository.
You can uncomment the repository.root.directory entry and set it to a hard-coded path on your file system. This is typically recommended if you plan to use
Guvnor in a production environment enyways.
HTH