I have discovered a problem with an SBS2003 server running in a HyperV session. When I copy a large file (100mb+) to the virtual SBS2003 server it will time out and fail. All internal file copy operations work okay. It is like the Hyper-V virtual Nic is faulty. The system was using an internal NIC so I tried adding an Intel NIC and made it the NIC for the SBS 2003 virtual machine and left the original NIC for the host server. Same issue. When I copy a large test file (1gb VHD) to the SBS2003 drive(s) or domain controller I get a "Read-only" error message after 5-10 seconds and the copy aborts. Small files copy okay. No problem with virtualized 2003 member servers. I tried turning off large packets and also tried 100 megabit through flow control
System is running with one virtual processor.
My version of Hyper-V is 6.00.6001.1816