Q) I notice that as well as accessing documents stored in SP document libraries via the web site we can also access documents via an explorer network share - ie \\sharepointsite\site\.... My question is are these documents real and being maintained in addition to the data already to be found in the db or is it some clever virtualisation trick? Does any one have any insight that they can share with me? The reason I need to know is that our SP server is beginning to run out of disk space (not the DB server) and I want to check that it's not down to SP files being stored locally.
A) In SharePoint, Documents (Document Library) are actually Stored in your SQL Server. And We need to know how WEBDAV UNC's work in sharepoint, Check this Whitepaper -
Understanding and Troubleshooting the SharePoint Explorer View http://www.microsoft.com/downloads/details.aspx?FamilyID=C523AC7A-5724-48BE-B973-641E805588F4&displaylang=en. This WhitePaper discuss in detail about windows WEBDAV and FPRPC protocol , windows WEBDAV Client and Explorer View, should be good starting point to understand WEBDAV and Explorer View