Description of problem:
When online resizing a virtio and virtio-scsi disk, the guests (CentOS 7, RHEL 7.3) do not detect the disc change online. Instead, I have to shut down the VMs and start them again - then they see the new disk size.

Version-Release number of selected component (if applicable):
I am using RHEV 4.1 and Red Hat Ceph Storage 2.2.
Ceph is attached to RHEV via OpenStack Cinder.

How reproducible:
everytime at customer environment

Steps to Reproduce:
1. install rhev (manager + host + storage)
2. add OpenStack Cinder as external provider
3. create vm with cinder as virtual disk
4, live grow cinder

Actual results:
new size is detected only when vm is powered down and powered up

Expected results:
new size will be detected in RHEL without shutting down the vm

Additional info:
feature is tech preview, so you can consider this as RFE as well