I've noticed that Xenserver it's quite slow and cause too much high disk activity (measured from my NAS) with windows server 2008-12-12R2 .
This happened from so much time (i used Xenserver from 6.2 version) but today , testing a Proxmox and an Hyper-v environment these S.O. are much much faster than Xenserver Hypervisor. It's understandable for Hyper-v (Same Microsoft technology) but ... Proxmox.. on my test Proxmox it's faster on Windows.
When I say faster I mean that system is more responsive and the differences are bigs.
This is normal ? Have you some advices of this ?