linux下kvm虚拟机的搭建

Posted 2020-12-04

安装kvm虚拟机工具：
yum -y install
qemu-kvm #为kvm提供底层支持
libvirt-client #virsh等软件
libvirt-daemon #libvirtd服务守护进程
libvirt-daemon-drive-qemu #virsh的qemu驱动
virt-install #系统安装工具
virt-manager #图形管理工具
virt-v2v #虚拟机迁移工具
virt-p2v #物理机迁移工具

在真机上添加一条路由转发，以方便后期的虚拟机访问外网
vim /etc/sysctl.d/70-system.conf
net.ipv4.ip_forward = 1

配置虚拟网卡参数
cd /etc/libvirt/qemu/networks/autostart/
cp default.xml /etc/libvirt/qemu/networks/vnet1.xml
cp default.xml /etc/libvirt/qemu/networks/vnet2.xml
cd /etc/libvirt/qemu/networks/
vim vnet1.xml
例：
<network>
<name>veth1</name>
<forward mode=‘nat‘/>
<bridge name=‘veth1‘/>
<ip address=‘192.168.1.254‘ netmask=‘255.255.255.0‘>
<dhcp>
<range start=‘192.168.1.100‘ end=‘192.168.1.200‘/>
</dhcp>
</ip>
</network>

vim vnet2.xml
<network>
<name>veth2</name>
<forward mode=‘nat‘/>
<bridge name=‘veth2‘/>
<ip address=‘192.168.2.254‘ netmask=‘255.255.255.0‘>
</ip>
</network>

删除真机防火墙，关闭selinux
yum -y remove firewall
setenforce 0
编辑selinux开机不启用
vim /etc/selinux/config

编辑虚拟网卡设置
cd /etc/sysconfig/network-scripts/
vim ifcfg-veth1
cp ifcfg-veth1 ifcfg-veth2
vim ifcfg-veth2

vim /etc/sysconfig/network-scripts/ifcfg-veth1
例：
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes
NAME=veth1
DEVICE=veth1
ONBOOT=yes
IPADDR=192.168.1.254
PREFIX=24
GATEWAY=192.168.1.254
DNS1=114.114.114.114

vim /etc/sysconfig/network-scripts/ifcfg-veth2
例：
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes
NAME=veth2
DEVICE=veth2
ONBOOT=no
IPADDR=192.168.2.254
PREFIX=24
GATEWAY=192.168.2.254
DNS1=114.114.114.114

定义虚拟网卡，并启用
在确定以关闭防火墙及selinux情况下，如有相关报错，先重启真机
cd /etc/libvirt/qemu/networks/
virsh net-define veth1.xml
virsh net-define veth2.xml
virsh net-start veth1
virsh net-start veth2
virsh net-autostart veth1
virsh net-autostart veth2

创建一个20G（大小看环境）模板镜像文件
cd /var/lib/libvirt/images/
qemu-img create -f qcow2 node.qcow2 20G

virt-manager
创建新虚拟机
装centos7 的系统
可以选择网络安装
分配空间，选择自定义，使用之前创建的node.qcow2
分区只分一个根， 标准分区
语言用默认英文
关闭kdump

进入虚拟机查看IP地址，veth1之前定义是dhcp分配的ip地址
拷贝真机yum源至虚拟机

在虚拟机上安装所需的工具
yum -y install net-tools vim-enhanced iproute bash-completion

vi /etc/sysconfig/network
NOZEROCONF="yes"

vi /etc/sysconfig/network-scripts/ifcfg-eth0
NAME="eth0"
ONBOOT=yes
NETBOOT=yes
IPV6INIT=yes
BOOTPROTO=dhcp
TYPE=Ethernet
DEVICE="eth0"

vi /etc/sysconfig/grub
添加一行，以方便真机console字符连接
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200n8"

应用该配置文件：
grub2-mkconfig -o /boot/grub2/grub.cfg

配置模板镜像完毕后关机：
halt -p

cd /etc/libvirt/qemu
cp centos7.0.xml /root/
vim /root/centos7.0.xml
9 <name>centos7.0</name>
改成 <name>node0</name>方便执行脚本
以下标注内容均需删除：
以下标注内容均需删除：
以下标注内容均需删除：

10 <uuid>c04d4f3a-a3b9-4ddb-93ea-2361636d6e6f</uuid>
65 <mac address=‘52:54:00:22:f4:de‘/>

所有<address type=....../>
所有<controller type=‘usb‘.......</controller>

因为之前还有一块veth2虚拟网卡，故添加以下语句：
<interface type=‘network‘>
<source network=‘veth2‘/>
<model type=‘virtio‘/>
</interface>

删除之前安装定义的模板
virsh undefine centos7.0

注：以下脚本上传博客后seq语句会缺失字符，请自行添加
注：以下脚本上传博客后seq语句会缺失字符，请自行添加
注：以下脚本上传博客后seq语句会缺失字符，请自行添加

ln -s /root/kvm.sh /sbin/kvm.sh
ln -s /root/setip.sh /sbin/setip.sh

附：虚拟机创建脚本
vim kvm.sh
#!/bin/bash
read -p "请输入需要创建的虚拟机数量：" num
read -p "请输入起始的虚拟机编号：node" x

for i in seq $num
do
cp /root/centos7.0.xml /var/lib/libvirt/qemu/node$[i-1+x].xml
sed -i ‘s/name>node.</name>node‘$[i-1+x]‘</‘ /var/lib/libvirt/qemu/node$[i-1+x].xml
sed -i ‘s/node..img/node‘$[i-1+x]‘.img/‘ /var/lib/libvirt/qemu/node$[i-1+x].xml
virsh define /var/lib/libvirt/qemu/node$[i-1+x].xml
qemu-img create -b /var/lib/libvirt/images/node.qcow2 -f qcow2 /var/lib/libvirt/images/node$[i-1+x].img 20G
done

附：字符界面定义虚拟机ip脚本
vim setip.sh
#!/bin/bash
yum -y install expect tcl
read -p "请输入虚拟机起始编号(1~): node" vm
read -p "请输入需要创建起始ip地址(例:192.168.2.5)：" cip
read -p "请输入需要创建连续的主机数(1~)：" num
ip=echo $cip|awk -F. ‘{print $4}‘
net=echo $cip|awk -F. ‘{print $1"."$2"."$3}‘
case $net in
192.168.1)
cnet=eth0;;
192.168.2)
cnet=eth1;;
*)
echo "错误的IP地址！"
exit
esac
#for i in seq $num
#do
#expect <<eof
#spawn virsh start node$[vm+i-1]
#expect "#" {send " "}
#exit
#eof
#done

#sleep 18

for i in seq $num
do
echo $net.$[i+ip-1]>>/tmp/host
expect <<EOF
spawn virsh console node$[vm+i-1]
expect "换码符为 ^]" {send " "}
expect "login:" {send "root "}
expect "Password:" {send "123456 "}
expect "]#" {send "nmcli connection add con-name $cnet ifname $cnet type ethernet "}
expect "]#" {send "nmcli connection modify $cnet ipv4.method manual ipv4.addresses $net.$[i+ip-1]/24 ipv4.gatew
ay $net.254 ipv4.dns 114.114.114.114 connection.autoconnect yes "}expect "]#" {send "nmcli connection up $cnet "}
expect "]#" {send "hostnamectl set-hostname node$[i+ip-1].cn "}
interact
exit
EOF
done
#yum -y install pssh

for i in seq $num
do
expect <<EOF
spawn ssh-copy-id -o StrictHostKeyChecking=no $net.$[ip+i-1]
expect "password:" {send "123456 "}
expect "#" {send " "}
exit
EOF
done

echo ‘nmcli connection show| awk ‘"‘/--/{print "‘$‘"2}‘"‘>/tmp/et.txt‘>/tmp/et.sh
echo for i in ‘cat /tmp/et.txt‘>>/tmp/et.sh
echo do >> /tmp/et.sh
echo nmcli connection delete "$"i >>/tmp/et.sh
echo done >> /tmp/et.sh
chmod +x /tmp/et.sh
pscp.pssh -h /tmp/host /new/gao.repo /etc/yum.repos.d/gao.repo
pscp.pssh -h /tmp/host /tmp/et.sh /tmp/et.sh
pssh -h /tmp/host bash /tmp/et.sh
rm -rf /tmp/host