I am using a Nimbus Cloud Middleware which in turn use Python libvirt binding to start VM's. Hypervisor is KVM. # virsh -c qemu:///system version Compiled against library: libvir 0.8.7 Using library: libvir 0.8.7 Using API: QEMU 0.8.7 Running hypervisor: QEMU 0.12.1 Some time i get the error in the Nimbus Logs it says : UnexpectedError: Problem creating the VM: monitor socket did not show up.: No such file or directory I googled but this particular not able to find. I checked the /var/log/libvirt/qemu/wrksp-427.log 2012-05-23 10:09:13.494: starting up LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin HOME=/root USER=root LOGNAME=root QEMU_AUDIO_DRV=none /usr/libexec/qemu-kvm -S -M rhel6.1.0 -enable-kvm -m 2024 -smp 2,sockets=2,cores=1,threads=1 -name wrksp-427 -uuid e8c5c171-392c-02e4-b43c-b0b4279e55c5 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/wrksp-427.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -boot c -drive file=/VM/Nimbus/secureimages/wrksp-427/<a href="http://param-vm.cdacb.in/cloud/5f4f0dcd//RHEL5.5_64bit_MPI,if=none,id=drive-ide0-0-0,format=raw">param-vm.cdacb.in/cloud/5f4f0dcd//RHEL5.5_64bit_MPI,if=none,id=drive-ide0-0-0,format=raw</a> -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,fd=24,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=a2:aa:bb:2e:d6:58,bus=pci.0,addr=0x3 -usb -vnc <a href="http://127.0.0.1:22">127.0.0.1:22</a> -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 10:09:13.512: 14116: info : libvirt version: 0.8.7, package: 18.el6 (Red Hat, Inc. <<a href="http://bugzilla.redhat.com/bugzilla">http://bugzilla.redhat.com/bugzilla</a>>, 2011-04-18-10:28:30, <a href="http://x86-008.build.bos.redhat.com">x86-008.build.bos.redhat.com</a>) 10:09:13.512: 14116: debug : virCgroupNew:566 : New group /libvirt/qemu/wrksp-427 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 0:cpu at /cgroup/cpu in 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 1:cpuacct at /cgroup/cpuacct in 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 2:cpuset at /cgroup/cpuset in 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 3:memory at /cgroup/memory in 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 4:devices at /cgroup/devices in 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 5:freezer at /cgroup/freezer in 10:09:13.513: 14116: debug : virCgroupDetect:245 : Detected mount/mapping 6:blkio at /cgroup/blkio in 10:09:13.513: 14116: debug : virCgroupMakeGroup:497 : Make group /libvirt/qemu/wrksp-427 10:09:13.513: 14116: debug : virCgroupMakeGroup:509 : Make controller /cgroup/cpu/libvirt/qemu/wrksp-427/ 10:09:13.513: 14116: debug : virCgroupMakeGroup:509 : Make controller /cgroup/cpuacct/libvirt/qemu/wrksp-427/ 10:09:13.514: 14116: debug : virCgroupMakeGroup:509 : Make controller /cgroup/cpuset/libvirt/qemu/wrksp-427/ 10:09:13.514: 14116: debug : virCgroupMakeGroup:509 : Make controller /cgroup/memory/libvirt/qemu/wrksp-427/ 10:09:13.514: 14116: debug : virCgroupSetValueStr:290 : Set value '/cgroup/cpu/libvirt/qemu/wrksp-427/tasks' to '14116' 10:09:13.714: 14116: debug : virCgroupSetValueStr:290 : Set value '/cgroup/cpuacct/libvirt/qemu/wrksp-427/tasks' to '14116' 10:09:14.467: 14116: debug : virCgroupSetValueStr:290 : Set value '/cgroup/cpuset/libvirt/qemu/wrksp-427/tasks' to '14116' 10:09:15.467: 14116: debug : virCgroupSetValueStr:290 : Set value '/cgroup/memory/libvirt/qemu/wrksp-427/tasks' to '14116' 2012-05-23 10:09:16.537: shutting down There is no suspect in the log file. Any Ideas??? -- <div>Thanks </div><div> </div>Vipul Borikar <div>"Our task must be to free ourselves...by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty."</div>