virsh的名称的含义是virtualization shell。它有两种工作模式：
立即模式

[root@localhost kvm-vm]# virsh list --all
 Id    Name                           State
----------------------------------------------------
 -     centos7.0                      shut off
 -     ubuntu16.04                    shut off
 -     vmtest01                       shut off
 -     vncvm01                        shut off

交互模式

virsh # list --all
 Id    Name                           State
----------------------------------------------------
 -     centos7.0                      shut off
 -     ubuntu16.04                    shut off
 -     vmtest01                       shut off
 -     vncvm01                        shut off

kvm配置文件存放路径为：

[root@localhost kvm-vm]# ls /etc/libvirt/qemu/
autostart      networks         vmtest01.xml     vncvm01.xml
centos7.0.xml  ubuntu16.04.xml  vncvm01-bak.xml

kvm基本功能管理

1. 查看虚拟机状态：virsh list --all

   virsh list --all
    Id    Name                           State
   ----------------------------------------------------
    -     centos7.0                      shut off
    -     ubuntu16.04                    shut off
    -     vmtest01                       shut off
    -     vncvm01                        shut off
   

2. 虚拟机开机与关机

   开启：virsh start vmtest01 
   virsh list
   Id    Name                           State
   ----------------------------------------------------
   1     vmtest01                       running
   
   关闭：virsh shutdown vmtest01 
   Domain vmtest01 is being shutdown
   

3. 强制关闭系统电源：virsh destroy vmtest01

   virsh list
   Id    Name                           State
   ----------------------------------------------------
   2     vmtest01                       running
    
   virsh destroy vmtest01 
   Domain vmtest01 destroyed
   virsh list --all
   Id    Name                           State
   ----------------------------------------------------
   -     vmtest01                       shut off
   

4. 通过配置文件启动虚拟机

   virsh create /etc/libvirt/qemu/vmtest01.xml 
   Domain vmtest01 created from /etc/libvirt/qemu/vmtest01.xml
   virsh list 
   Id    Name                           State
   ----------------------------------------------------
   3     vmtest01                       running
   

5. 挂起、恢复虚拟机

   挂起：virsh suspend vmtest01 
   Domain vmtest01 suspended
   virsh list --all
   Id    Name                           State
   ----------------------------------------------------
   3     vmtest01                       paused
    
   恢复：virsh resume vmtest01 
   Domain vmtest01 resumed
   virsh list --all
   Id    Name                           State
   ----------------------------------------------------
   3     vmtest01                       running
   

6. 配置虚拟机实例伴随宿主机自动启动

   virsh autostart vmtest01 
   Domain vmtest01 marked as autostarted
   ll /etc/libvirt/qemu/autostart/
   total 0
   lrwxrwxrwx. 1 root root 30 Apr 28 21:25 vmtest01.xml -> /etc/libvirt/qemu/vmtest01.xml
   
   关闭自启动
   virsh autostart --disable vmtest01 
   Domain vmtest01 unmarked as autostarted
   

7. 导出虚拟机配置

    virsh dumpxml vmtest01 > /etc/libvirt/qemu/vm.bak
   

8. 删除虚拟机

   virsh list --all
    Id    Name                           State
   ----------------------------------------------------
    -     centos7.0                      shut off
    -     ubuntu16.04                    shut off
    -     vmtest01                       shut off
    -     vncvm01                        shut off
   virsh undefine vmtest01 
   Domain vmtest01 has been undefined
   virsh list --all
    Id    Name                           State
   ----------------------------------------------------
    -     centos7.0                      shut off
    -     ubuntu16.04                    shut off
    -     vncvm01                        shut off
   

9. 恢复被删除的虚拟机

   #使用刚才备份的文件
   virsh define /etc/libvirt/qemu/vm.bak 
   Domain vmtest01 defined from /etc/libvirt/qemu/vm.bak
   virsh list --all
    Id    Name                           State
   ----------------------------------------------------
    -     centos7.0                      shut off
    -     ubuntu16.04                    shut off
    -     vmtest01                       shut off
    -     vncvm01                        shut off
   

克隆虚拟机

 virt-clone -o vmtest01 -n vm_clone -f /kvm-vm/vm_clone.qcow2
 Clone 'vm_clone' created successfully
 参数说明：
 -o：指定被克隆虚拟机
 -n：克隆机名称
 -f：指定克隆机文件位置与名称
 virsh list --all
 Id    Name                           State
----------------------------------------------------
-     vm_clone                       shut off

虚拟机快照

virsh snapshot-create-as vmtest01 kz1
Domain snapshot kz1 created
参数说明：
snapshot-create:创建快照
-as：快照取名
virsh snapshot-list vmtest01 
Name                 Creation Time             State
------------------------------------------------------------
kz1                  2020-04-28 21:40:50 +0800 shutoff
##查看当前快照信息（部分截图）
virsh snapshot-current vmtest01 
<domainsnapshot>
  <name>kz1</name>			##快照名称
  <state>shutoff</state>
  <creationTime>1588081250</creationTime>
  <memory snapshot='no'/>

恢复快照
连接虚拟机后创建文件：

[root@localhost ~]# touch tt
[root@localhost ~]# echo "hello" > tt 
[root@localhost ~]# cat tt
hello

---

##恢复快照
virsh snapshot-revert vmtest01 kz1 
##验证
[root@localhost ~]# ls
anaconda-ks.cfg

---

##删除快照
virsh snapshot-list vmtest01 
Name                 Creation Time             State
------------------------------------------------------------
kz1                  2020-04-28 21:40:50 +0800 shutoff
virsh snapshot-delete vmtest01 kz1 
Domain snapshot kz1 deleted
virsh snapshot-list vmtest01 
Name                 Creation Time             State
------------------------------------------------------------