ping

yum install qemu-kvm libvirt virt-install

робуем другое зеркало.
libvirt-daemon-driver-storage- FAILED                                          
http://mirrors.powernet.com.ru/centos/7.5.1804/updates/x86_64/Packages/libvirt-daemon-driver-storage-iscsi-3.9.0-14.el7_5.6.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.powernet.com.ru; Unknown error"
Пробуем другое зеркало.
virt-manager-common-1.4.3-3.el FAILED                                          
http://mirror.awanti.com/centos/7.5.1804/os/x86_64/Packages/virt-manager-common-1.4.3-3.el7.noarch.rpm: [Errno 14] curl#6 - "Could not resolve host: mirror.awanti.com; Unknown error"
Пробуем другое зеркало.
libvirt-python-3.9.0-1.el7.x86 FAILED                                          
http://mirrors.powernet.com.ru/centos/7.5.1804/os/x86_64/Packages/libvirt-python-3.9.0-1.el7.x86_64.rpm: [Errno 14] curl#6 - "Could not resolve host: mirrors.powernet.com.ru; Unknown error"
Пробуем другое зеркало.


Error downloading packages:
  libvirt-daemon-driver-nodedev-3.9.0-14.el7_5.6.x86_64: [Errno 256] No more mirrors to try.
  libvirt-daemon-3.9.0-14.el7_5.6.x86_64: [Errno 256] No more mirrors to try.
  libvirt-3.9.0-14.el7_5.6.x86_64: [Errno 256] No more mirrors to try.
  libvirt-daemon-driver-qemu-3.9.0-14.el7_5.6.x86_64: [Errno 256] No more mirrors to try.