Finding lots of bad behaviour here: [Fri Apr 17 23:44:04.590626 2015] [:error] [pid 31714] [client 127.0.0.1:38103] PHP Warning: libvirt_list_networks(): this function is not supported by the connection driver: virConnectNumOfNetworks [Fri Apr 17 23:44:04.590655 2015] [:error] [pid 31714] [client 127.0.0.1:38103] PHP Fatal error: Out of memory (allocated 524288) (tried to allocate 18446744073709551608 bytes) There's no way to check if this exists... I noticed the following about versions: - this system works fine (Git): libvirt 1.2.9 Array ( [libvirt.release] => 9 [libvirt.minor] => 2 [libvirt.major] => 1 [connector.version] => 0.5.0 [connector.major] => 0 [connector.minor] => 5 [connector.release] => 0 ) - this system has problems (Git) libvirt 1.2.12 Array ( [libvirt.release] => 12 [libvirt.minor] => 2 [libvirt.major] => 1 [connector.version] => 0.5.0 [connector.major] => 0 [connector.minor] => 5 [connector.release] => 0 [type.release] => 12 [type.minor] => 2 [type.major] => 1 ) When I do a version check to only do network list for version under .12, I get this: [Fri Apr 17 23:44:43.608308 2015] [:error] [pid 31689] [client 127.0.0.1:38216] PHP Warning: libvirt_network_get(): this function is not supported by the connection driver: virNetworkLookupByName Which causes a cascade of other errors if you're not checking for problems each step along the way. Kash Pande Jentu Technologies, Inc http://jentu-networks.com