I suddenly ran into a problem related to inconsistent IIS filesystem path today when creating a new web application in SharePoint 2010. SharePoint threw the message
The filesystem path for the IIS website does not point to and NTFS drive. SharePoint requires all web servers in the farm to be configured identically. This requirement extends to drive letter name
Because the environment was highly secured by several hardening guidelines so checking around IIS hardening was flashed in my mind first. Indeed there was a rule requiring the IIS root to be moved to another location. The registry path HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InetStp contains a key named PathWWWRoot that specify the root folder of IIS. After changing to the same location with other SharePoint web application’s locations and performed iisreset, I managed to create a new web application.
Make sure if you are going to change the IIS filesystem path, you need to migrate all because SharePoint doesn’t support inconsistent IIS path for different web applications.