If you followed Apple's recent announcement at their WWDC conference then you would know that they just released a Thunderbolt to Gigabit Ethernet adapter. So, why am I talking about this? Well if you are running ESXi 5 on an Apple Mac Mini like me, then you are probably wondering if you can get another network interface on the Mini as it only has a single network adapter. The answer is YES!
To get ESXi 5 to recognize the Thunderbolt adapter, you will need to download and install an additional Broadcom driver (tg3 3.123b.v50.1) or you can create a customized ISO with the driver built in using the steps outlined here for a new installation.
UPDATE (12/21): A custom ESXi ISO is no longer needed, you can use ESXi 5.0 Update 2 which includes the necessary driver to support Thunderbolt Ethernet adapter. Please take a look at this article here for the details.
If you are just installing the driver on an existing ESXi 5 installation, extract the offline bundle and upload to your ESXi host and run the following command:
esxcli software vib install -d /vmfs/volumes/mini-local-datastore-1/tg3-3.123b.v50.1-offline_bundle-682322.zip
Here is the output from ESXCLI on how ESXi sees the Thunderbolt adapter:
As you can see, it shows up with no description for the device and this is the same when running lspci, it just shows up as a network controller from Broadcom. This is not a big deal, but I assume this has something to do with the high numbering of the vmnic instead of being vmnic1 it's vmnic32.
I also performed some basic network testing by yanking the ethernet cable on the onboard network adapter and ensured traffic continued to flow and vice versa with the other Thunderbolt adapter. Everything works beautifully and now you can have some network redundancy built into your Mac Mini or if you need the throughput for all those VMs you plan on running 😉
Big thanks to Randy K. for hooking me up with a Thunderbolt adapter!