I've been testing a new samsung 960 evo nvme drive i just got, and running tests on it in a guest shows a minimum of double the cpu time on the host as it does on the guest. Somehow a guest running a single thread iozone or fio test can use 4+ cores on the host side at 50-100%. I have debian's 4.9.13 kernel installed on the host (4.9.2 on the guest), and kvm/qemu 2.8.0. I'm using libvirt and virt-manager to set up the guest, with a lvm volume set up on the nvme drive, and exporting a couple volumes to the guest which it then either uses lvm on, or testing is done raw on a secondary volume. (I've tried both) Host is a consumer box with an AMD 970 board + FX-8320, and 32GB ram. Guest is currently allocated 8 threads, and 1GB ram which it is currently only using 111MB of while fio is running. I'm curious to know if this is expected behavior, misconfiguration on my end, or a misunderstanding of how things work? I'd appreciate any insight or help anyone is able and willing to provide. -- Thomas Fjellstrom thomas@xxxxxxxxxxxxx
