I did this experiment: on VM I started watching a video on youtube. While video was in progress I started migration. Migration did not complete until video was not finished.
I did another experiment: I installed a web server on VM. I then started an httperf stress test. As before migration did not complete until the stress test was closed.
Is this normal?
Yes, I'd consider this to be normal (depending on what network equipment you're using).
Live migration requires that the entire contents of the VM's RAM be synchronized between hosts. If there is a high rate of change in RAM contents during the migration, synchronization may never complete, or may take a very long time.
If you're currently using 1G uplinks, you may consider upgrading to 10G NICs and a 10G switch.
