slow down on disk operiations

[michabbs]

I have one qemu Windows server vm and a couple of lxc containers in one node. Whenever I perform (inside the host machine) any disk-expensive operation (like "dd 100GB-zvol") - the Windows guest slows down. Actually this is not so unexpected... but the problem is that it slows down too much, so that the vm becomes unusable for human. :-( (It speeds up back when the disk operation is over.)
Any way to prioritize kvm a little bit more, so that Windows was still usable?

node: ZFS, 64G ram, 24 threads
guest: 24 ram, 8 threads

 

[wolfgang]

Hi,
Proxmox VE has for expensive copy operation limiters [1].
if you use tools like dd you can uns cstream.

1.) https://pve.proxmox.com/wiki/Manual:_datacenter.cfg