Libvirt/virsh

Create snapshot

$ virsh snapshot-create-as [vmname] snapshot1 "Before installation" --disk-only --atomic

$ virsh start [vmname]

$ virsh destroy [vmname]

$ virsh reboot [vmname]

$ sudo su - stack -c "virsh reboot undercloud"

$ virsh shutdown [vmname]

Create a libvirt persistent pool and start it:

$ virsh pool-define-as --type=dir --name=default --target=/var/lib/libvirt/images
$ virsh pool-autostart default
$ virsh pool-start default

/var/lib/libvirt/images is where QEMU QCOW images will be stored, so make sure this directory is attached to a file system with sufficient storage.