虛擬機無法啓動

由於kvm所在的機器啓用了SELINUX，後來將之關閉，關閉之後，發現kvm的虛擬機無法啓動

現象

虛擬機無法啓動

報錯信息

啓動過程中的報錯信息如下：

[root@ESRoller ~]# virsh start zabbix
error: Failed to start domain zabbix
error: unsupported configuration: Unable to find security driver for label selinux

libvirt中的日誌也提示報錯：
[root@ESRoller ~]# tail -f /var/log/libvirt/libvirtd.log
2016-06-20 09:54:41.724+0000: 2388: error : qemuRemoveCgroup:754 : internal error Unable to find cgroup for zabbix
2016-06-20 09:54:41.724+0000: 2388: warning : qemuProcessStop:4403 : Failed to remove cgroup for zabbix
2016-06-20 09:54:41.725+0000: 2388: error : qemuAutostartDomain:284 : Failed to autostart VM 'zabbix': unsupported configuration: Unable to find security driver for label selinux
2016-06-20 09:54:41.734+0000: 2388: error : virSecurityManagerGenLabel:376 : unsupported configuration: Unable to find security driver for label selinux
2016-06-20 09:54:41.741+0000: 2388: error : qemuRemoveCgroup:754 : internal error Unable to find cgroup for roller
2016-06-20 09:54:41.741+0000: 2388: warning : qemuProcessStop:4403 : Failed to remove cgroup for roller
2016-06-20 09:54:41.742+0000: 2388: error : qemuAutostartDomain:284 : Failed to autostart VM 'roller': unsupported configuration: Unable to find security driver for label selinux
2016-06-20 09:59:07.548+0000: 2378: error : virSecurityManagerGenLabel:376 : unsupported configuration: Unable to find security driver for label selinux
2016-06-20 09:59:07.561+0000: 2378: error : qemuRemoveCgroup:754 : internal error Unable to find cgroup for zabbix

造成原因

由於機器開機狀態時，將SElinux的狀態信息save在虛擬機中，導致SElinux關閉之後，虛擬找不到對應的label，從而導致vm啓動失敗。

解決方法

virsh edit domain_name查看虛擬機的配置文件中，是否有selinux標籤的相關設置，如果有，則將其刪除，再啓動vm。如果沒有，則可能已經保存在vm狀態中，將原有的狀態刪除即可(對應路徑/var/lib/libvirt/qemu/save)，如下：

[root@ESRoller ~]# virsh managedsave-remove zabbix
Removed managedsave image for domain zabbix
 
[root@ESRoller ~]# virsh start zabbix
Domain zabbix started
 
[root@ESRoller ~]# virsh list 
 Id    Name                           State
----------------------------------------------------
 4     zabbix                         running

如果配置配置文件中有selinux相關的配置，將其刪除，期配置類似於：

<seclabel type='dynamic' model='selinux' relabel='yes'>
    <label>system_u:system_r:svirt_t:s0:c625,c859</label>
    <imagelabel>system_u:object_r:svirt_image_t:s0:c625,c859</imagelabel>
</seclabel>