Hi, I'm using libvirt/kvm with openstack. When vm has CPU stall, the instance can't be destroyed. I have asked the question on openstack user mailing list and received no answers in weeks. Here is one example: # virsh destroy instance-00000085 error: Failed to destroy domain instance-00000085 error: Failed to terminate process 61222 with SIGKILL: Device or resource busy # lsof -p 61222 # ps -f -p 61222 UID PID PPID C STIME TTY TIME CMD 107 61222 1 68 Jan24 ? 9-23:06:19 [qemu-system-x86] <defunct> The log in /var/log/libvirt/libvirtd.log: 2014-02-08 03:21:31.597+0000: 2177: error : virProcessKillPainfully:315 : Failed to terminate process 61222 with SIGKILL: Device or resource busy Restart libvirt-bin service did not solve the problem. virsh shutdown/reboot just hang. Maybe that is because the CPU in vm is stalled. I wonder if there is some way to destroy (or rebuild) dead instance without rebooting the hypervisor. Any suggestions is welcome. The software I am running: hypervisor os: ubuntu 12.04.3 hypervisor kernel: 3.8.0-35-generic vm os: ubuntu 12.04 vm kernel: 3.2.0-56-virtual openstack: havana libvirt: 1.1.1-0ubuntu8~cloud2 Thanks, Yuanle