I just installed dnn 5.1.2 on a Windows 2008 Server.  I tried turning on the file based caching but I am not seeing any files that are created in the Portals/_default/Cache  folder (the install only contains one portal).  I'm expecting to see files that have a GUID for a name in this folder but no files are ever created.

This is how I set it up.  In the web.config I set 

    <add key="EnableCachePersistence" value="true" />

    <caching defaultProvider="FileBasedCachingProvider">
      <providers>
        <add name="FileBasedCachingProvider" type="DotNetNuke.Services.Cache.FileBasedCachingProvider.FBCachingProvider, DotNetNuke.Caching.FileBasedCachingProvider" providerPath="~\Providers\CachingProviders\FileBasedCachingProvider\" />
      </providers>
    </caching>

On the host settings page under 'Performance Settings'  I set

Page State Persistence = Page

Module Caching Method = Disk

Cache Setting'= Heavy

Authenticated Cacheability  = Server

Still no evidence of any files being created.  What am I missing?

Thanks in advance!