Environment:
Two physical hosts
- Cloudstack 4.11.3
- Verified that there are no bandwidth limits in place on any of the
templates or in global settings.
Two isolated networks ("Client" and "Server")
- Each has a vrouter with a public and private address
- One Windows 2016 VM on each network (running the latest virtio drivers)
- each node running latest version of Iperf3 to test throughput
Testing/Observation:
If the Client VM and the vrouter for the isolated Client network are on the
same physical host, we see symmetrical throughput in the 2 Gbps range,
whether we run iperf in regular mode or in reverse mode (iperf -R).
If the Client VM and the vrouter for the isolated Client network are on
different physical hosts, we are seeing 25% of the throughput running iperf
in regular mode vs running it in reverse mode.
Has anyone encountered this issue before? If we change the Client VM to
Linux (either CentOS 7 or Ubuntu) OR we use the E1000 driver, we see
symmetrical throughput in our tests, no matter where the vrouter is in
relation to the Client VM.
--
Steve Fuller
[email protected]
