In the Using multi-core features document we could use some more details on the step 6, as it doesn't properly explain where do we can set the data folder for each core.

For now this is how it looks:

In both conf directories you must then copy the contents of the folder extension/ezfind/java/solr/conf/* and adapt the Solr dataDir.

Here's a suggestion:

In both conf directories you must then copy the contents of the folder extension/ezfind/java/solr/conf/* and adapt the Solr dataDir setting on solrconfig.xml for each core.

<dataDir>${solr.data.dir:/your/path/to/solr/data}</dataDir>

The same improvement would be useful for the same document for the previous versions.