Hi Fatih!
I have setup Proxmox on Hetzner, 3-4 Months ago…
With Hetzner, it depends very much on what you ordered. My client ordered a dedicated server specifically for Proxmox (Hetzner specifically supports Proxmox!), there was NO virtualization inside virtualization!
(1 SSD for OS, 2*3TB HDs as ZFS RAID1 for VMs)
What is specifically a PITA with Hetzner is that if you order additional IPs (As my client did), they are routed behind the Proxmox.
We had 2 IPs in the 80er range, and a whole small subnet in the 170er range. As the 170 had to be routed behind the Proxmox, I was forced to waste an IP for the router (An 80er). I used a virtualized OPNsense as an Internal Firewall (2 Virtual NICs, one on vmbr0, one on vmbr1, our “Internal” network with a 10.x.x.x IP.
With OPNsense and VPN, I was able to configure the other hosts, all working now as expected.
The internal NethServer is running AD, and Zabbix Monitoring…
The whole system is actually quite performant, more than I expected!
My 2 cents
Andy