When mounting an iso using the built-in tools from windows server 2012 or windows 8 the operation fails. (dialog box 'sorry there was a problem mounting the file)
When setting 'server max protocol = SMB2_02' the mount works perfectly.
When doing a network trace the last operation is a FSCTL_LMR_REQUEST_RESILIENCY,
to which the reply is STATUS_INVALID_DEVICE_REQUEST. According to msdn (http://msdn.microsoft.com/en-us/library/ee380168.aspx) this should be STATUS_NOT_SUPPORTED for protocol versions higher than 2.002
See bug #10159 for an explanation of why this fails. HyperV strictly requires FSCTL_LMR_REQUEST_RESILIENCY when used against SMB 2.10 or higher.
Almost certainly a HyperV component is in use here. We are working with Microsoft about the backup case. We may simply be too late, but I'll alert them to this additional use case.
This much is now fixed on the Microsoft side, please use the hotfix at KB 2920193 for Window 2012 and Windows 8.
The rest of the issue is confirmed as a duplicate of 10159, which will track any fixes we get from Microsoft for 2012R2, and any change we make in the long term to support this feature.
*** This bug has been marked as a duplicate of bug 10159 ***