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I've made some research and now understand that Hyper-V runs alongside the Windows Server (i.e. it is not an in-windows app). Therefore it would be hard to achieve the ESX performance close to ESX or Hyper-V even when deploying on linux. Or wouldn't it? Maybe considering a partition as disk for virtualbox? Idle Linux overhead isn't this much, is it?
In the case of ESXi it's about the clustering, filesystem/network virtualization, management and orchestration for hundreds of servers, disaster recovery, enterprise security/software integrations, and so on. That VirtualBox requires a client OS is just a footnote in the comparison of functionality.
E.g. Parallel's is only useful for people looking to run VMs locally on their Mac, but Hyper-V can be anything from that for a Windows PC to a full-blown headless hypervisor cluster with HA, shared volumes, replication, etc.
For several of the common categories, these are my takes:
- Traditional Enterprise: Nutanix [paid] if money is available, otherwise Hyper-V [paid] if a large Microsoft contract is already in place. If neither fit: fall through to acting like an SMB.
- SMB/Modern Mid-Sized Enterprise: Cloud [paid] only and/or Proxmox [free/paid]
- Tech Company: Doesn't matter, they'll do whatever sounds cool that year and make it work well enough
- Home Lab: Proxmox [free/paid]
- Windows PC: Hyper-V [free w/ Windows] (it's meh, but it's integrated - doubly so if you plan on using WSL on the side).
- Mac PC: Parallels [paid] if you need a GPU accelerated Windows guest, UTM [free] otherwise.
- Linux PC: QEMU+KVM [free], the choice of (optional) GUI client is up to preference.
Some extra notes by solution:
- Nutanix: Enterprises were staring to use this more and more even prior to the VMware sale. It's definitely the spiritual successor of traditional VMware usage in the data center. A bit less full of themselves, for now at least, than VMware ever managed to keep themselves (IMO).
- Proxmox: Has a bit of a habit of feeling like it always ends up a little broken by the time you've used an install/cluster for 6 months, but is by far the best option for the homelabber type use case (even ignoring that it's free as a reason). It's basically like someone configured KVM with what you want to be able to just (try to) use it without thinking about what's underneath, while still having access to the underneath to un-stick it in certain situations. Also does host-native containers! I never did have the guts to pitch my company try to run anything production on a cluster, but they do have reasonably priced support plans and advanced feature tiers for that.
- Parallels: Kind of sucks for the price, but there isn't anything else on macOS with the same GPU acceleration for Windows.
- Hyper-V: I think this is mostly still around because it helps Microsoft stay sticky at companies when the yearly renewal comes up. That said, it's alright - and it's also integrated into Windows in some pretty nifty ways for local use these days.
- UTM: Fantastic QEMU client for macOS, worth giving a few bucks for even though it's free.