OP here. One thing we mentioned in the blog but probably didn’t emphasize enough is how deeply ZFS is integrated into the UI.

With Sylve, you rarely need to touch the CLI. Snapshots, datasets, ZVOLs, even flashing images directly to ZVOLs, it’s all handled from the UI in a straightforward way.

That tight ZFS integration also lets us build more flexible backup workflows. You can back up VMs, jails, or entire datasets to any remote machine that supports SSH + ZFS. This is powered by Zelta (https://zelta.space) (which is embedded directly into the Go backend), so it’s built-in rather than something you bolt on.

In Proxmox, you can achieve similar things, but it’s less intuitive and usually involves setting up additional components like Proxmox Backup Server.

> They explain a lot of things but I can't see the advantage over prox other than they wanted to use it.

A huge, totally obvious, advantage is that FreeBSD isn't using systemd. I'm now nearly systemd-free, if not for Proxmox. But my VMs are systemd free. And, by definition, my containers too (where basically the entire point is that there's a PID 1 for the service and that PID 1, in a container is not systemd).

So the last piece missing for me is getting rid of Proxmox because Proxmox is using systemd.

I was thinking about going straight to FreeBSD+bhyve (the hypervisor) but that felt a bit raw. FreeBSD+Sylve (using bhyve under the hood) seems to be, at long last, my way out of systemd.

I've got several servers at home with Proxmox but I never, on purpose, relied too much on Proxmox: I kept it to the bare minimum. I create VMs and use cloudinit and tried to have most of it automated and always made it with the idea of getting rid of Promox.

I've got nothing against Proxmox but fuck systemd. Just fuck that system.

Sometimes unification can be an advantage.

I run Proxmox at home, but now that I have been drinking the NixOS koolaid over the past 2 years, all of my homelab problems suddenly look like Nix-shaped nails.

Honestly asking, in which cases nested virtualization is useful?

Thanks, I hadn't heard of it either.

Without looking at the Sylve docs, I'll conjecture that it has deeper integration with ZFS. With a foundation on FreeBSD, there is a likelihood Sylve can support ZFS-on-root rollbacks better than hacking it into Proxmox. A rollback capability is why I'm looking for Proxmox alternatives. In the Linux world, Talos Linux and IncusOS provide A/B updates which achieve a similar rollback capability. With something based on FreeBSD, your "immutable" OS and all of it's data can be treated equally as ZFS datasets. There's also a higher risk that a Linux kernel update will break ZFS.

> What does Sylve provide that proxmox doesn't?

A Un*x system that doesn't use systemd as an init system.

Bhyve is quite cool but no nested virt which means you cannot nest vm_enter/exit calls with EPT pages so you cannot virtualize within those guests. I found this crucial. For instance Qubes OS won't run in Bhyve by any means.

Anecdotally, Bhyve has worked in FreeBSD for a decade now. Eventually it got ported to Illumos because it was better than their implementation of QEMU.

If you are unsure of bhyve's abilities then why not test yourself? Speculation and guessing about stability or testing is useless without seeing if it works in your application.