I came across this bug report from RedHat when researching and issue where our newly deployed RHEL 7.4 VMs on Hyper-V would go into a hang state at times during the host backup process. Lots to good work done here to find a potential solution by upgrading to the latest kernel 3.10.0-843.el7.
See the full bug report (Bug 1502601) and process here: https://bugzilla.redhat.com/show_bug.cgi?id=1502601