安装kvm

文档参考：
CentOS7 ：http://www.linux-kvm.org/page/HOWTO#RHEL.2FCentOS_7
CentOS6 ：https://wiki.centos.org/zh/HowTos/KVM --> 白皮书: 第一册， 第二册

• 1.a,创建虚拟机
• 1.b,运行/停止虚拟机
• 1.c,查看虚拟机

---

• 虚拟机配置调整：内存，磁盘，cpu数
• 虚拟机的两大主要文件：image, xml文件

##  1,  image路径： 
root@controller:/var/lib/libvirt/images# ls
cent7-clone.qcow2  cent7.qcow2  centos7.0.qcow2
 
 ##  2,  虚拟机xml配置文件路径： 
root@controller:/etc/libvirt/qemu# ls
cent7-clone.xml  cent7.xml  centos7.0.xml  networks

1, 虚拟机：生命周期管理

• a， 创建虚拟机 (virt-install)

#内存：1G,   cup: 2,   硬盘:30G
###执行命令后，满足条件就会弹出centos的安装界面
 virt-install \
 --name c6 \
 --ram=1024 \
 --vcpus=2 \
 --network=bridge:br0 \
 --disk path=/var/lib/libvirt/images/c6.img,size=30  \
 --cdrom /CentOS-6.10-x86_64-minimal.iso

• b,查看/运行/停止虚拟机 (virsh list/ start/ shutdown,destroy)

root@controller:/home/wang# virsh list 
 Id    Name                           State
----------------------------------------------------
 6     centos7.0                      running
 9     cent7                          running

root@controller:~/openstack# virsh dominfo cent7
Id:             20
Name:           cent7
UUID:           a566d8e4-ec6f-42d7-9d31-8d0d3ce5f09a
OS Type:        hvm
State:          running
CPU(s):         2
CPU time:       197.0s
Max memory:     2097152 KiB
Used memory:    1048576 KiB
Persistent:     yes
Autostart:      disable
Managed save:   no
Security model: apparmor
Security DOI:   0
Security label: libvirt-a566d8e4-ec6f-42d7-9d31-8d0d3ce5f09a (enforcing)

################# autostart, start,  shutdown, reboot  //pause,  resume
root@controller:/etc/network# virsh  shutdown cent7
Domain cent7 is being shutdown

root@controller:/etc/network# virsh  list --all
 Id    Name                           State
----------------------------------------------------
 6     centos7.0                      running
 -     cent7                          shut off

• 3, 删除虚拟机

root@controller:/ # cat /usr/local/bin/kvm-delete.sh
read -p '输入(要删除的虚拟机)：'  name
echo "....going to delete ..$name"

#1,destroy
virsh destroy $name

#2,undefine
virsh undefine $name

#3,del image
rm -f /var/lib/libvirt/images/$name.qcow2
echo "delete kvm $name --> ok...."

2, kvm登录虚拟机

• virsh console xx

#virt-viewer -c qemu:///system VMachinename
virt-viewer  cent7

3, 虚拟机内存调整

## setmaxmem                      change maximum memory limit
## setmem                            change memory allocation
#虚拟机开机后，动态内存扩展(加上--config表示写入到配置文件，永久生效)
virsh setmaxmem centos7  9GB --config
virsh  setmem centos7    8GB  --config

## setvcpus                       change number of virtual CPUs
## setvcpu                        attach/detach vcpu or groups of threads

4, 复制/克隆虚拟机

virt-clone命令： 需要关闭虚拟机再操作

root@controller:~/openstack# virt-clone -o cent7 -n cent7_2 --auto-clone
正在分配 'cent7_2.qcow2'                                                                                           | 5.0 GB  00:00:23     

成功克隆 'cent7_2'。
root@controller:~/openstack# virsh list --all
 Id    Name                           State
----------------------------------------------------
 18    stack                          running
 -     cent7                          shut off
 -     cent7_2                        shut off

root@controller:~/openstack# ls /var/lib/libvirt/images/
cent7_2.qcow2  cent7.qcow2  centos7.0.qcow2  stack.qcow2

root@controller:~/openstack# ls /etc/libvirt/qemu
cent7_2.xml  cent7.xml  networks  stack.xml

若没有关闭虚拟机来克隆就会报以下错误：

root@controller:~# virsh list
 Id    Name                           State
----------------------------------------------------
 11    centos7.0                      running
 12    cent7                          paused

root@controller:~# virt-clone -o cent7 --auto-clone
WARNING  设置图形设备端口为自动端口，以避免相互冲突。
ERROR    Couldn't create storage volume 'cent7-clone.qcow2': 'internal error: Child process (/usr/bin/qemu-img convert -f qcow2 -O qcow2 -o compat=1.1,lazy_refcounts /var/lib/libvirt/images/cent7.qcow2 /var/lib/libvirt/images/cent7-clone.qcow2) unexpected exit status 1: qemu-img: Could not open '/var/lib/libvirt/images/cent7.qcow2': Failed to get shared "write" lock
Is another process using the image?

5,虚拟机重命名

把上面的cent7-clone 这个刚克隆的虚拟机重命名(先停止虚拟机）–> cent7_2

root@controller:~# virt-clone -o cent7 --auto-clone
正在分配 'cent7-clone.qcow2'                                                                                       |  40 GB  00:00:47     
成功克隆 'cent7-clone'。

#启动克隆好的虚拟机
root@controller:~# virsh  start cent7
Domain cent7 started
root@controller:~# virsh  start cent7-clone
Domain cent7-clone started

root@controller:~# virsh list
 Id    Name                           State
----------------------------------------------------
 11    centos7.0                      running
 13    cent7                          running
 14    cent7-clone                    running
 
# 1, xml修改
root@controller:~# virsh dumpxml cent7-clone > /etc/libvirt/qemu/cent7_2.xml
root@controller:/etc/libvirt/qemu# ls
cent7_2.xml  cent7-clone.xml  cent7.xml    networks
####修改旧的名字， 为新的名字
root@controller:/etc/libvirt/qemu# grep cent7-clone cent7_2.xml 
  <name>cent7-clone</name>
      <source file='/var/lib/libvirt/images/cent7-clone.qcow2'/>
root@controller:/etc/libvirt/qemu# sed -i s/cent7-clone/cent7_2/g cent7_2.xml 

# 2, image文件重命名
root@controller:/var/lib/libvirt/images# ls
cent7-clone.qcow2  cent7.qcow2 
root@controller:/var/lib/libvirt/images# mv cent7-clone.qcow2 cent7_2.qcow2

# 3,  废弃旧的虚拟机，使用新的虚拟机
root@controller:~# virsh list
 Id    Name                           State
----------------------------------------------------
 13    cent7                          running
 14    cent7-clone                    running

root@controller:~# virsh  shutdown  cent7-clone
Domain cent7-clone is being shutdown
root@controller:/etc/libvirt/qemu# virsh undefine cent7-clone  
Domain cent7-clone has been undefined
root@controller:/etc/network# ls /etc/libvirt/qemu/
cent7_2.xml    cent7.xml      centos7.0.xml  networks/  

root@controller:/etc/libvirt/qemu# virsh list --all
 Id    Name                           State
----------------------------------------------------
 13    cent7                          running

root@controller:/etc/libvirt/qemu# virsh define cent7_2.xml
Domain cent7_2 defined from cent7_2.xml
root@controller:/etc/libvirt/qemu# virsh start cent7_2
viDomain cent7_2 started

root@controller:/etc/libvirt/qemu# virsh list
 Id    Name                           State
----------------------------------------------------
 13    cent7                          running
 15    cent7_2                        running

6, kvm导出virtualbox/vmware虚拟机

• 把kvm的虚拟机磁盘文件导出为vdi,vmdk即可在virtualbox或vmware中使用此虚拟机

sudo qemu-img convert /var/lib/libvirt/images/win7.qcow2 -O vdi ./win7.vdi