OpenStack离不开QEMU[1~3]。

[1] Building Up to OpenStack — QEMU and Your Cloud, http://ibm-blue-box-help.github.io/help-documentation/gettingstarted/userguides/qemu_article/

[2] Building Up to OpenStack II -- Improving Cloud Performance, http://ibm-blue-box-help.github.io/help-documentation/gettingstarted/userguides/Improving_Cloud_Performance/

[3] (关于qcow2和openstack)9 tips to properly configure your OpenStack Instance, https://redhatstackblog.redhat.com/2017/01/18/9-tips-to-properly-configure-your-openstack-instance/