Builds fail due to severe speed drop in CI network

The switch which is supposed to give 2xGbit/s connection to coin hosts occasionally drops the speed to about 1Mbit/s. This can be reproduced by doing iperf traffic from one VM guest to another or to the Compellent. For a while the speed is > 900Mbit/s but soon drops to few Mbits/s.

Update: This only seems to happen if there is a VM included. See comments below.

Some times CI network is very slow and this causes provisioning + build breakages. At least most of this slowness is caused by the network throughput issue.

• From IRC logs:
  • "Anything wrong with ci-files01-hki? That thing seems to be SLOW"
  • (which makes provisioning fail)