Windows on Proxmox NVMe

[masgo]

I want to set up a new Proxmox server which will be mainly used for a Windows VM. Proxmox will be installed on normal SSDs. These SSDs will also be used for other VMs.

The main VM will be a Windows Database Server which should use NVMe drives. I have 2 PCIe x16 Slots and want to use them for 2 NVMe cards. For reliability, I want to have RAID 1. Since this is a DB server, the main goal is to have high IOPS. The bandwidth is not that important.

The question is, what will give me the best Performance? ZFS raid1 or passthrough to Windows and Windows software RAID 1.

Also: if I pass them to Windows, is there any chance of ever (offline) migrating the VM to another server? Migration would probably mean dd of the NVMe drives to another server??

or I could have 2x NVME -> 2x ZFS non-raid -> windows software RAID 1, but I guess this has the worst performance?

 

[Stefan_R]

The question is, what will give me the best Performance? ZFS raid1 or passthrough to Windows and Windows software RAID 1.

I think the only reliable of finding that out is by benchmarking on your specific setup. I would personally recommend ZFS mirror on the host and then assign that to Windows and use it as one disk there, simply because you get the benefits of ZFS and easy management.

PCIe passthrough of NVMe disks is certainly faster for accessing a single disk, but doing the RAID calculations in the VM might offset that benefit quite a bit. Again, test on your hardware, no one-size-fits-all answer here.

Also: if I pass them to Windows, is there any chance of ever (offline) migrating the VM to another server? Migration would probably mean dd of the NVMe drives to another server??

If you use ZFS on the host, you can even live migrate the VM. No problem there at all. PCIe passthrough disables PVE migration entirely, but as you said, you can simply clone the data on the drives and move the config file (/etc/pve/qemu-server/<vmid>.conf) manually (adjusting values to the new system of course).

or I could have 2x NVME -> 2x ZFS non-raid -> windows software RAID 1, but I guess this has the worst performance?

Please just don't do that

 

[masgo]

Thx for the reply. I will probably go with a traditional zfs raid1 and hope the performance is good enough. Having to do dd+config altering for a migration is way to painful.