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博客地址：http://blog.csdn.net/qq_21398167
原博文地址：http://blog.csdn.net/qq_21398167/article/details/46874843
问题1 ：
service libvirtd status no connection driver available for qemu:///system
參考 ：http://echorequest.info/?p=70
解决的方法： modify /etc/libvirt/libvirt.conf setting to uri_default = "qemu:///system".
问题2 ：
ERROR nova.virt.libvirt.driver [-] Connection to libvirt failed: no connection driver available for qemu:///system
解决的方法： yum update device-mapper
问题3 ：
failed to load module /usr/lib64/libvirt/connection-driver/libvirt_driver_storage.so /usr/lib64/libvirt/connection-driver/libvirt_driver_storage.so: symbol dm_task_get_info_with_deferred_remove, version Base not defined in file libdevmapper.so.1.02 with
link time reference
failed to load module /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so: undefined symbol: virStorageFileCreate
參考：Solutin: http://www.adminz.in/2015/04/libvirtd-error-after-package-update.html
Solution: http://lists.openstack.org/pipermail/openstack/2014-December/010628.html
解决：/etc/nova/nova.conf compute_driver = libvirt.LibvirtDriver
问题4 ：
nova.openstack.common.threadgroup HypervisorUnavailable: Connection to the hypervisor is broken on host
解决：export LIBVIRT_DEFAULT_URI=qemu:///system