Description of problem:
It is impossible to limit bandwidth used for storage migration tasks. This can cause storage network and SAN congestion issues preventing normal cluster operation

Version-Release number of selected component (if applicable):
vdsm-4.14.7-3.el6ev.x86_64

How reproducible:
always

Steps to Reproduce:
1. iSCSI SAN and all hosts connected over a 1 gbps link using dedicated storage network
2. start a storage migration

Actual results:
3. SPM saturates 1 gbps link on the SAN port
4. other hosts have problems reaching the SAN

Expected results:
3. bandwidth limit configured on SPM, it only uses that limit for storage migrations
4. other hosts in the cluster have no issues reaching the SAN

Additional info:
technology and link speed may vary. THe important point here is that storage migrations may saturate the SAN and negatively affect other hosts and VMs on them.