Hello,
The server itself is a Cisco UCSC-C240-M3S2. The device I am trying to passthrough is a onboard USB2.0 controller. Perhaps that could be the problem...
On Tuesday I am planning on upgrading a IBM x3100 M4 server running ESXi 5.0.0 Update 2. Installed in the server is a D-Link PCI Express card that is currently working successfully in PCI Passthrough mode to one of the VMs.
I am unsure at this stage whether to upgrade to ESXi 5.0.0 Update 3 or to 5.1.0 Update 2. Considering the issues I'm having with 5.1.x Update x I'm tempted to just upgrade to ESXi 5.0.0 Update 3.
The only reason I am considering updating to 5.1.0 Update 2 is because another host in a different branch office is running that version so would like to keep it the same.
Guess what I can do is upgrade the host to 5.1.0 Update to, test the pci passthrough of the dlink USB3.0, if it fails roll back the host to 5.0.0 Update 3. (as long as I make sure not to upgrade the hardware of the VM's...)