RHEL7.0在安装完成virt-manager后，启动libvirtd服务进程
[root@demo Desktop]# systemctl enable libvirtd
[root@demo Desktop]# systemctl start libvirtd
在使用virt-manager命令启动虚拟机管理软件时，提示unable to connect to libvirt
Unable to connect to libvirt.
no connection driver available for qemu:///system
Libvirt URI is: qemu:///system
Traceback (most recent call last):
File "/usr/share/virt-manager/virtManager/connection.py", line 969, in _open_thread
self._backend.open(self._do_creds_password)
File "/usr/share/virt-manager/virtinst/connection.py", line 157, in open
open_flags)
File "/usr/lib64/python2.7/site-packages/libvirt.py", line 105, in openAuth
if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: no connection driver available for qemu:///system
查看libvirtd的状态
[root@demo Desktop]# systemctl status libvirtd
libvirtd.service - Virtualization daemon
Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled)
Active: active (running) since Mon 2015-08-31 21:27:48 CST; 4min 47s ago
Docs: man:libvirtd(8)
Main PID: 9837 (libvirtd)
CGroup: /system.slice/libvirtd.service
└─9837 /usr/sbin/libvirtd
Aug 31 21:27:48 demo.example.com libvirtd[9837]: libvirt version: 1.2.8, package: 16.el7_1.3 (CentOS BuildSystem <)
Aug 31 21:27:48 demo.example.com libvirtd[9837]: failed to load module /usr/lib64/libvirt/connection-driver/libvirt_driver_storage...ference
Aug 31 21:27:48 demo.example.com libvirtd[9837]: failed to load module /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so...eCreate
Aug 31 21:27:48 demo.example.com libvirtd[9837]: Module /usr/lib64/libvirt/connection-driver/libvirt_driver_lxc.so not accessible
Aug 31 21:27:48 demo.example.com systemd[1]: Started Virtualization daemon.
Aug 31 21:28:19 demo.example.com systemd[1]: Started Virtualization daemon.
Aug 31 21:29:14 demo.example.com libvirtd[9837]: no connection driver available for qemu:///system
Aug 31 21:29:14 demo.example.com libvirtd[9837]: End of file while reading data: Input/output error
Hint: Some lines were ellipsized, use -l to show in full.
此时可能是驱动程序的安装有问题，更新device-mapper包
[root@demo Desktop]# yum update device-mapper
重启libvirtd服务
[root@demo Desktop]# systemctl restart libvirtd
[root@demo Desktop]# systemctl status libvirtd
libvirtd.service - Virtualization daemon
Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled)
Active: active (running) since Mon 2015-08-31 21:34:23 CST; 7s ago
Docs: man:libvirtd(8)
Main PID: 10082 (libvirtd)
CGroup: /system.slice/libvirtd.service
├─10082 /usr/sbin/libvirtd
├─10185 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --dhcp-script=/usr/libexec/libvirt_leaseshelper
└─10186 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --dhcp-script=/usr/libexec/libvirt_leaseshelper
Aug 31 21:34:23 demo.example.com systemd[1]: Started Virtualization daemon.
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: started, version 2.66 cachesize 150
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: compile time options: IPv6 GNU-getopt DBus no-i18n IDN DHCP DHCPv6 no-Lua TFTP no...et auth
Aug 31 21:34:26 demo.example.com dnsmasq-dhcp[10185]: DHCP, IP range 192.168.122.2 -- 192.168.122.254, lease time 1h
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: reading /etc/resolv.conf
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: using nameserver 202.103.44.150#53
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: using nameserver 202.103.24.68#53
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: read /etc/hosts - 4 addresses
Aug 31 21:34:26 demo.example.com dnsmasq[10185]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses
Aug 31 21:34:26 demo.example.com dnsmasq-dhcp[10185]: read /var/lib/libvirt/dnsmasq/default.hostsfile
Hint: Some lines were ellipsized, use -l to show in full.
此时libvirtd服务显示为正常，没有出现报错，再次运行virt-manager，可以正常连接