I had issues running it on ESXi and getting it to recognize SMART and had issues with reboots. Since ESXi gives the main drive a virtual ID every time you reboot the ESXi host machine, Rockstor would not be happy when you fired up that VM. It can be done but from my experience you can’t just fire up a VM and let it run. As much as it would be nice to have it on a VM having a dedicated machine to run Rockstor + Storage isn’t an expensive. I found several old Dell T5500 work stations on ebay very cheap and they are overkill for the task.