Will qemu+kvm+libvirt work?

Question

KVM

Hello, comrades!
Or friends in misfortune ...
I confess right away: I did not deal with large virtualization systems. Clusters, there are all sorts ...
I used kvm + libvirt a lot, but not in a cluster. On a single, dedicated server.
Now, work and tasks have changed. We need big solutions. A whole zoo of virtualization systems is already in use. oVirt, Proxmox, Hyper-V and some other crap based on kvm.
The most depressing impression was made by oVirt. Something terribly heavy and stupid. Proxmox, oddly enough, made a much better impression.
So a timid idea appeared - to stir up the kvm + libvirt system.
Minus, as it were. There is no complete control system. Virt-manager is good on a solo server. But! There is an extensive API. C, java, python, php! Pooh, the most miserable documentation, but! The functions of puff are very close to those of phyton, which is very well documented.
So, there are no particular problems, stir up your control system!
libvirt has a huge advantage in my opinion! He is light! Proxmox or oVirt is much heavier. Well, libvirt's console support is no match.
Therefore, now the idea arose to raise a cluster on kvm + libvirt + ..... with a dedicated server for storing VM images.
For now, I am planning a test cluster of 3 servers: 2 servers for VM execution and one for storage (like NAS).
In the long run, in theory, this system should be scaled up and crowd out the rest.
The approximate number of spinning VMs is thousands, if not tens of thousands.
What threatens the solution on kvm+ libvirt+peacemaker+....?

Answer 1

The fact that, unlike many ready-made virtualization systems, you will have to write and configure a lot yourself. This can only be done by a large service provider