Hello
When start service libvirtd by
service libvirtd start
OS: CentOS 6.5 libvirt: libvirt-daemon-1.2.5-1.mira1.x86_64
https://www.redhat.com/mailman/listinfo/libvirt-users is the official mailing list for the libvirt daemon, maybe you can ask in there and get better support.
Does anyone know the reason?
This mailing list is for the general usage of the CentOS system, I am afraid that not many experts about libvert could be found here.
If you ask in the most appropriate mailing list, you may get the quickest and the most helpful assistance.