KVM 安装和基础使用文档

# KVM

明确自己学kvm 只是为了自己方便

快速拉起机器

##  安装kvm

**1.验证机器是否可以安装KVM**

```shell
egrep -o 'vmx|svm' /proc/cpuinfo
```

![image-20231213152128251](https://oss.yc-monster.work/picture/image-20231213152128251.png)

**2.关闭防火墙与selinux**

```shell
# systemctl stop firewalld
# systemctl disable firewalld
	Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
	Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
# setenforce 0
# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
```

**3.KVM安装**

```shell
# yum -y install qemu-kvm qemu-kvm-tools qemu-img libvirt libvirt-python libvirt-client virt-manager virt-install virt-viewer bridge-utils libguestfs-tools

```

libvirt #虚拟机管理
virt #虚拟机安装克隆
qemu-kvm #管理虚拟机磁盘

**4.配置网桥**

因为虚拟机中网络，我们一般都是和公司的其他服务器是同一个网段，所以我们需要把 KVM服务器的网卡配置成桥接模式。这样的话KVM的虚拟机就可以通过该桥接网卡和公司内部 其他服务器处于同一网段

这里网卡是ens33，所以用br0来桥接ens33网卡

```shell
//新建br0
# vim /etc/sysconfig/network-scripts/ifcfg-br0 
TYPE=Bridge
DEVICE=br0
NM_CONTROLLED=no
BOOTPROTO=static
NAME=br0
ONBOOT=yes
IPADDR=192.168.118.128
NETMASK=255.255.255.0
GATEWAY=192.168.118.2
DNS1=8.8.8.8

# vim /etc/sysconfig/network-scripts/ifcfg-ens33 
\\注释掉IPv4和IPv6、UUID等
TYPE=Ethernet
##PROXY_METHOD=none
##BROWSER_ONLY=no
BOOTPROTO=static
##DEFROUTE=yes
##IPV4_FAILURE_FATAL=no
##IPV6INIT=yes
##IPV6_AUTOCONF=yes
##IPV6_DEFROUTE=yes
##IPV6_FAILURE_FATAL=no
##IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
##UUID=c32fb339-09d4-4f69-b6f4-cb78dd1c819e
DEVICE=ens33
ONBOOT=yes

\\新增
BRIDGE=br0
NM_CONTROLLED=no

```

```shell
# systemctl restart network
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000
    link/ether 00:0c:29:ab:f5:e4 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::20c:29ff:feab:f5e4/64 scope link 
       valid_lft forever preferred_lft forever
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:0c:29:ab:f5:e4 brd ff:ff:ff:ff:ff:ff
    inet 192.168.118.128/24 brd 192.168.118.255 scope global br0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feab:f5e4/64 scope link 
       valid_lft forever preferred_lft forever

```

### 验证安装成果

```shell
#启动服务
systemctl start libvirtd
systemctl enable libvirtd
#验证安装结果
lsmod | grep kvm
kvm_intel             188740  0 
kvm                   637289  1 kvm_intel
irqbypass              13503  1 kvm

# virsh --version
4.5.0
# virt-install --version
1.5.0
# ln -s /usr/libexec/qemu-kvm  /usr/bin/qemu-kvm         //映射文件到bin下
# ll /usr/bin/qemu-kvm
lrwxrwxrwx 1 root root 21 5月  31 15:09 /usr/bin/qemu-kvm -> /usr/libexec/qemu-kvm

#查看网桥信息
# brctl show
bridge name	bridge id		STP enabled	interfaces
br0		8000.000c29abf5e4	no		ens33
virbr0		8000.5254000e4000	yes		virbr0-nic

```

## 操作KVM

查看虚拟机

```shell
//开机
# virsh start centos7-01
域 centos7-01 已开始

//"温柔"关机
# virsh shutdown centos7-01
域 centos7-01 被关闭

//强制关机
# virsh destroy centos7
域 centos7-02 被删除         //这个显示真是无语，还好实际上只是关机

# virsh list --all
 Id    名称                         状态
----------------------------------------------------
 -     centos7                        关闭
 -     centos7-01                     关闭
 -     centos7-02                     关闭
 -     win2016A                       关闭
 - 
//删除虚拟机
# virsh destroy win2016A 
# virsh vol-delete 
```

新建虚拟机

```shell
virt-install \
--name=test1 \
--ram 16384 --vcpus=8 \
--disk path=/vm/images/centos/test1/test1.qcow2,size=100,format=qcow2,bus=virtio \
--location=/vm/iso/centos/CentOS-7.6-x86_64-DVD-1810.iso \
--network bridge=virbr0,model=virtio \
--vnc --vnclisten=0.0.0.0 --vncport=5900 --password=123456 \
--autostart \
-d
```

克隆虚拟机

```shell
virt-clone --check disk_size=off -o yc07 -n yc09 -f /vm/images/centos/yc09/yc09.qcow2
```

虚拟机快照

```shell
#创建快照
# virsh snapshot-create-as centos7 --name centos7.snap1
#列出所有快照
# virsh snapshot-list centos7
#恢复快照
# virsh snapshot-revert centos7 --snapshotname centos7.snap2
#删除快照
 virsh snapshot-delete  yc0 --snapshotname  
```

删除虚拟机

```shell
#停止主机
virsh destroy win7
#删除主机定义
virsh undefine win7
#删除KVM虚拟机文件
rm -rf /opt/abc/win7.qcow2
```