More details on the subject: I suppose it is a nested KVM issue because it raised after I enabled the nested KVM feature. Without it, anyway, the second level VMs are unusable in terms of performance. I am using CentOS 7 with: kernel: 3.10.0-327.22.2.el7.x86_64 qemu-kvm:1.5.3-105.el7_2.4 libvirt:1.2.17-13.el7_2.5 on both the baremetal and the compute VM. The only workaround now is to shutdown the compute VM and start it back from baremetal with virsh start. A simple restart of the compute node doesn't help. It looks like the qemu-kvm process corresponding to the compute VM is the problem. Laurentiu În dum., 14 aug. 2016 la 00:19, Laurentiu Soica <laurentiu at soica.ro> a scris: > Hello, > > I have an OpenStack setup in virtual environment on CentOS 7. > > The baremetal has *nested KVM* enabled and 1 compute node as a VM. > > Inside the compute node I have multiple VMs running. > > After about every 3 days the VMs get inaccessible and the compute node > reports high CPU usage. The qemu-kvm process for each VM inside the compute > node reports full CPU usage. > > Please help me with some hints to debug this issue. > > Thanks, > Laurentiu > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20160814/6cf64c21/attachment-0006.html>