EMCopy Hangs host Windows with Hyper-V

I´m working in transfer a lot (+/- 500.000.000) of litle files (+/- 100k each) from a solution with clariion, celerra gw, rainfinity and centerra to a new aquisition - Isilon.

To do that, I create a virtual machine with windows 2008 R2 x64 on a host Windows 2008 R2 x64 and try to use EMCopy to copy the files.

I start the copy with these parameters:

emcopy64_V4.12.exe \\source\share "\\dest\share" /o /s /d /th 65 /c /r:3 /w:1

The command start as normal, but after half hour the virtual machine and host hangs (ping not respond, cannot login) - the solution is a hard boot on host.

After reboot, I tried again and the same thing happens after same time aprox.

I continue testing and every time that hangs, I need a hard boot on host. After a few times, I try these parameter, reducing the threads

emcopy64_V4.12.exe \\source\share "\\destiny\share" /o /s /d /th 6 /c /r:3 /w:1

And they run stable for one weekend.

In my final test I put to run the original parameter with 65 threads on Host, not in a virtual machine, and with these, EMCopy runs stable, today I close 4 days with no hangs, including use 4 cmd windows open and runnig together, each one with 65 threads.

Anyone already heard about something like these? A limitation of EMCopy with Hyper-V virtualization?

In my cenario I haven´t VMWare to test if these reply with other virtualization tecnology.

Just to know the hardware that I use is a Blade from DELL with blades powerEdge 610 and 10 Gbps ethernet interfaces, with 2xhexacore CPU and 96 GRAM.