(I'm sorry, I didn't find my original message but I provide the archive link: https://www.redhat.com/archives/libvirt-users/2015-January/msg00069.html ) I just tried the latest libvirt release (1.2.12), combined with the following qemu EL6 package from centos: qemu-kvm-0.12.1.2-2.448.el6_6.x86_64 Using 1.2.12 and this version of qemu-kvm, I still get the following error when trying to start a domain: error: Failed to start domain btcab0001ap.unix.banksys.be error: internal error: unable to execute QEMU command 'qom-list': The command qom-list has not been found The older qemu package (qemu-kvm-0.12.1.2-2.415.el6_5.14.x86_64) works just fine though (I also tried the qemu-rhev-packages for el6 from ovirt, but no change). I verified the changelog from libvirt 1.2.12 and the earlier suggested fix is in there (but doesn't seem to change anything): 2015-01-14 Pavel Hrdina <phrdina@redhat.com> qemu_monitor: introduce new function to get QOM path Now, I have activated libvirtd debug and these are the qom-list lines (I can provide the full logfile if wanted): 2015-02-11 14:10:33.259+0000: 13280: debug : virJSONValueToString:1528 : result={"execute":"qom-list","arguments":{"path":"/machine/unattached/device[0]"},"id":"libvirt-5"} 2015-02-11 14:10:33.259+0000: 13280: debug : qemuMonitorJSONCommandWithFd:290 : Send command '{"execute":"qom-list","arguments":{"path":"/machine/unattached/device[0]"},"id":"libvirt-5"}' for write with FD -1 2015-02-11 14:10:33.259+0000: 13280: info : qemuMonitorSend:972 : QEMU_MONITOR_SEND_MSG: mon=0x7fa62801cbf0 msg={"execute":"qom-list","arguments":{"path":"/machine/unattached/device[0]"},"id":"libvirt-5"} 2015-02-11 14:10:33.260+0000: 13278: info : qemuMonitorIOWrite:503 : QEMU_MONITOR_IO_WRITE: mon=0x7fa62801cbf0 buf={"execute":"qom-list","arguments":{"path":"/machine/unattached/device[0]"},"id":"libvirt-5"} 2015-02-11 14:10:33.261+0000: 13278: info : qemuMonitorIOProcess:399 : QEMU_MONITOR_IO_PROCESS: mon=0x7fa62801cbf0 buf={"id": "libvirt-5", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}} 2015-02-11 14:10:33.261+0000: 13278: debug : qemuMonitorJSONIOProcessLine:183 : Line [{"id": "libvirt-5", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}}] 2015-02-11 14:10:33.261+0000: 13278: debug : virJSONValueFromString:1361 : string={"id": "libvirt-5", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}} 2015-02-11 14:10:33.261+0000: 13278: info : qemuMonitorJSONIOProcessLine:203 : QEMU_MONITOR_RECV_REPLY: mon=0x7fa62801cbf0 reply={"id": "libvirt-5", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}} 2015-02-11 14:10:33.289+0000: 13280: debug : virJSONValueToString:1528 : result={"execute":"qom-list","arguments":{"path":"/machine/peripheral"},"id":"libvirt-7"} 2015-02-11 14:10:33.289+0000: 13280: debug : qemuMonitorJSONCommandWithFd:290 : Send command '{"execute":"qom-list","arguments":{"path":"/machine/peripheral"},"id":"libvirt-7"}' for write with FD -1 2015-02-11 14:10:33.289+0000: 13280: info : qemuMonitorSend:972 : QEMU_MONITOR_SEND_MSG: mon=0x7fa62801cbf0 msg={"execute":"qom-list","arguments":{"path":"/machine/peripheral"},"id":"libvirt-7"} 2015-02-11 14:10:33.289+0000: 13278: info : qemuMonitorIOWrite:503 : QEMU_MONITOR_IO_WRITE: mon=0x7fa62801cbf0 buf={"execute":"qom-list","arguments":{"path":"/machine/peripheral"},"id":"libvirt-7"} 2015-02-11 14:10:33.291+0000: 13278: info : qemuMonitorIOProcess:399 : QEMU_MONITOR_IO_PROCESS: mon=0x7fa62801cbf0 buf={"id": "libvirt-7", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}} 2015-02-11 14:10:33.291+0000: 13278: debug : qemuMonitorJSONIOProcessLine:183 : Line [{"id": "libvirt-7", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}}] 2015-02-11 14:10:33.291+0000: 13278: debug : virJSONValueFromString:1361 : string={"id": "libvirt-7", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}} 2015-02-11 14:10:33.291+0000: 13278: info : qemuMonitorJSONIOProcessLine:203 : QEMU_MONITOR_RECV_REPLY: mon=0x7fa62801cbf0 reply={"id": "libvirt-7", "error": {"class": "CommandNotFound", "desc": "The command qom-list has not been found", "data": {"name": "qom-list"}}} 2015-02-11 14:10:33.291+0000: 13280: debug : virJSONValueToString:1528 : result={"execute":"qom-list","arguments":{"path":"/machine/peripheral"},"id":"libvirt-7"} 2015-02-11 14:10:33.292+0000: 13280: debug : virJSONValueToString:1528 : result={"id":"libvirt-7","error":{"class":"CommandNotFound","desc":"The command qom-list has not been found","data":{"name":"qom-list"}}} 2015-02-11 14:10:33.292+0000: 13280: debug : qemuMonitorJSONCheckError:370 : unable to execute QEMU command {"execute":"qom-list","arguments":{"path":"/machine/peripheral"},"id":"libvirt-7"}: {"id":"libvirt-7","error":{"class":"CommandNotFound","desc":"The command qom-list has not been found","data":{"name":"qom-list"}}} 2015-02-11 14:10:33.292+0000: 13280: error : qemuMonitorJSONCheckError:381 : internal error: unable to execute QEMU command 'qom-list': The command qom-list has not been found (again: full log can be provided, but maybe that should be sent in private, I don't know if it is allowed as an attachment here). Any tips? Franky