Description of problem:
qemu-kvm-rhev-2.10.0 adds support for unsafe operation that we need when creating volumes (in order not to prepare and teardown the backing chain).
This change was already required for RHEL 7.5, refer to Bug 1535582.
Verified on 4.2.4.
[root@storage-ge4-vdsm3 ~]# repoquery --requires vdsm | grep libvirt-daemon-kvm
libvirt-daemon-kvm >= 3.9.0-14.el7_5.5
root@storage-ge4-vdsm3 ~]# repoquery --requires vdsm | grep qemu-kvm-rhev
qemu-kvm-rhev >= 10:2.10.0-21.el7_5.3
This bugzilla is included in oVirt 4.2.4 release, published on June 26th 2018.
Since the problem described in this bug report should be
resolved in oVirt 4.2.4 release, it has been closed with a resolution of CURRENT RELEASE.
If the solution does not work for you, please open a new bug report.