We have a new server setup for our Umbraco sites which is 5 x VMWare ESXi virtual Windows 2008 R2/IIS 7.5 servers running across 2 large physical servers.  All data is stored on a single Dell PowerVault MD3200i SAN and currently the IIS servers access the SAN via UNC which is served by FreeNAS.

I have setup a test site on one of the servers, with the AppPool running under the context of a windows user I created for the purpose as running using ApplicationPoolIdentity resulted in permissions errors.  This appears to work initially however after a short time I get the following errors in Event Viewer:

Failed to start monitoring changes to '\\fileserver\WebShare\Umbraco_Test' because the network BIOS command limit has been reached. For more information on this error, please refer to Microsoft knowledge base article 810886. Hosting on a UNC share is not supported for the Windows XP Platform.

I have tried making the registry changes referenced in the Microsoft KB article however this does not resolve the issue.

I have also tried setting FCNMode=2 and whilst this stopped the error above, it also prevented the client-facing site from reflecting any changes made to MasterPages/XSLT in the admin section until the AppPool was recycled.

If anyone has experienced any similar problems I would be grateful for some help with this issue as it is extremely frustrating at the moment.

Thanks

Paul