这里用之前克隆的虚拟机vm1-clone进行快照操作
注：
1.快照实际上做的是虚拟机的XML配置文件，默认快照XML文件在/var/lib/libvirt/qemu/snapshot/虚拟机名/下
2.快照仅仅支持qcow2磁盘格式的系统
一、虚拟机创建快照
[root@kvm01 ~]# virsh snapshot-create vm1-clone
Domain snapshot 1457941090 created
或创建快照的同一时候，再创建一个快照别名
[root@kvm01 ~]# virsh snapshot-create-as vm1-clone first_snap
二、查看虚拟机历史快照信息
[root@kvm01 ~]# virsh snapshot-list vm1-clone
Name Creation Time State
------------------------------------------------------------
1457941090 2016-03-14 15:38:10 +0800 running
ylhb 2016-03-14 16:23:04 +0800 running
三、查看虚拟机磁盘信息
[root@kvm01 ~]# qemu-img info /vm-images/vm1-clone.img
image: /vm-images/vm1-clone.img
file format: qcow2
virtual size: 10G (10737418240 bytes)
disk size: 3.7G
cluster_size: 65536
Snapshot list:
ID TAG VM SIZE DATE VM CLOCK
1 1457941090 212M 2016-03-14 15:38:10 00:50:13.868
2 ylhb 206M 2016-03-14 16:23:05 00:07:25.882
Format specific information:
compat: 1.1
lazy refcounts: true
能够看到里面已经含有虚拟机快照信息
四、查看当前快照信息
[root@kvm01 ~]# virsh snapshot-current vm1-clone
<domainsnapshot>
<name>ylhb</name>
<state>running</state>
<parent>
<name>1457941090</name>
</parent>
<creationTime>1457943784</creationTime>
<memory snapshot='internal'/>
五、恢复到之前快照
[root@kvm01 ~]# virsh snapshot-revert vm1-clone 1457941090
查看当前快照信息验证是否恢复成功：
[root@kvm01 ~]# virsh snapshot-current vm1-clone
<domainsnapshot>
<name>1457941090</name>
<state>running</state>
<creationTime>1457941090</creationTime>
<memory snapshot='internal'/>
<disks>
六、删除指定快照
[root@kvm01 ~]# virsh snapshot-delete vm1-clone 1457941090
Domain snapshot 1457941090 deleted