After upgrading Centos,RHEL,Scientific Linux 7.3 to 7.5, KVMs fail to start due to the upgrade:
1.yum install -y,....updates and upgrades your Linux System With no questions asked
"-y accepts everything and installs the packages"
Then when you run:
2.systemctl status -l libvirtd,
....shows that libvirtd service is not active, due to this,
libvirt_storage_backend_rbd.so undefined symbol: rbd_diff_iterate2 - "Error"