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I have a new HP DL120 G7 server with ESXi5. One VM is a Win2003 instalation and I have an external USB2.0 drive attached by USB Controller and USB Device.

I copy a 4GB file from external USB to server disk.

In the VM that takes up to 10 minutes.

On a native Win2003 that takes aprox. 3 minutes.

I have no explaination for that diference:

  • In any case the bottleneck is the USB connection, much slower than the disks (SAS, RAID1).
  • If the USB connection on the VM would be USB1.1 and not USB2.0 it would take much more time.
  • (The disk performance between server partitions on the VM is correct. -> see update)
  • Could be that my native box is extremely fast and the VM is the normal case.
  • ???


As mentioned, i tried with passthrough and it is much better.

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Is the USB drive connected via USB passthrough to the Windows VM? – ewwhite Jun 28 '12 at 7:29

The best performance in this scenario would be achieved by passing the USB controller to the virtual machine (VT-D). Otherwise, you'll only get USB 1.1 speeds.

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