Oh, it's better than that! If you're crazy enough, you can even multiboot multiple OSs on the same pool:) You do need to ensure that the pool features are sufficiently compatible between ZFS drivers (ex. you can't create a fully-featured pool with OpenZFS 2.1.6 on Linux and import it on OpenIndiana, last I checked), but it does work, empirically;)
A friend of mine suggested this and I didn't like the idea of putting the OS on there especially that it is a virtual machine. There are a couple of things that made this setup nice though: PCIe bifurcation (4x4x4x4) lanes straight to the CPU and PCIe passthrough in ESXi. From what I read that ZFS needs direct access to the underlying hardware. So, I just treat the OS as totally disposable and not worth backing up. I can spin up a VM in less than 2 mins if something were to happen to it.
