What is the best way to install proxmox ve 5 on a RAID1 array if there are only 4 disks?

Question

Debian

Hello!
I ask you not to throw tomatoes, gentlemen linuxoids, if something goes wrong, here is my question:
There is a server, it has 4 disks: 2x2Tb and 2x6Tb.
I suppose to do the following: create one raid (RAID1) from two 2TB disks and install Proxmox 5 on it. With the second pair of 6TB each, I also plan to make a raid (RAID1) and connect this raid as storage for backups in Proxmox. There will be a domain controller and file storage on the virtual machine in the promox (all on the same VM).
Have I made my plan correctly, or are there more optimal solutions with initial data.
On the second server, I did everything on ZFS RAID1 directly from the Proxmox installer, but there were SSD and 64Gb of RAM, on the same server there are ordinary server screws and 6Gb of RAM, so the idea with ZFS disappeared.
And what is the best way to put - first debian in the raid and on top of proxmox or first proxmox and then fasten the raid?
Thanks in advance, especially if you share links to proven manuals for Proxmox 5 and Debian 9 (on the net, as a rule, outdated information for version 4 and below).

Answer 1

I'll start from the end:
There is official documentation for installing Proxmox on Debian. Info about Proxmox 4 is still relevant.
It is better to keep backups on a separate machine (in case the motherboard dies, you have to rearrange disks to another machine, etc.)
I would make Raid10 4x2Tb for virtual machines, and the rest of the place in Raid1 for the system (and, possibly, backups)

Answer 2

I support Dmitry's proposal, especially since it will work very slowly on a "mirror" vm with Windows (domain controller), and even more so with file storage there! (do not forget for vm disk Windows virtio disk driver + write back + guest drivers for virtio from redhat).
I would suggest not to do storage in vm. Make it as an NFS volume inside the host, on the same raid10. Firstly, then you can access it from any vm (you will have AD clones, there will be other machines - everyone will get access to the data), and secondly, other servers will be able to reach. I also advise you to immediately raise LVM so that you can seamlessly expand partitions by connecting new disks.