kvm删除默认的NAT网卡

1.libvirt起来生辰的网卡信息（nat）
[root@linux-node2 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
    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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:0f:a1:08 brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.12/24 brd 192.168.56.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe0f:a108/64 scope link 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN 
    link/ether 52:54:00:36:61:85 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 500
    link/ether 52:54:00:36:61:85 brd ff:ff:ff:ff:ff:ff
[root@linux-node2 ~]# cd  /etc/sysconfig/network-scripts/

删除默认的网卡

[root@linux-node2 network-scripts]#  virsh net-destroy default 
Network default destroyed

[root@linux-node2 network-scripts]#  virsh net-undefine default 
Network default has been undefined

[root@linux-node2 network-scripts]# systemctl restart  libvirtd 
[root@linux-node2 network-scripts]# 
[root@linux-node2 network-scripts]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
    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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:0f:a1:08 brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.12/24 brd 192.168.56.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe0f:a108/64 scope link 
       valid_lft forever preferred_lft forever
[root@linux-node2 network-scripts]#

实在不行用这两条命令
ifconfig virbr0 down
brctl delbr virbr0

3.添加新的网卡

[root@linux-node2 network-scripts]# cat  ifcfg-br0 
DEVICE=br0
BOOTPROTO=none
ONBOOT=yes
TYPE=Bridge
IPADDR=192.168.56.12
NETMASK=255.255.255.0
GATEWAY=192.168.56.2
DEFROUTE=yes
PV4_FAILURE_FATAL=yes
IPV6INIT=no
DELAY=0
USERCTL=no
[root@linux-node2 network-scripts]# cat  ifcfg-eth0 
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
#IPV6_AUTOCONF=yes
#IPV6_DEFROUTE=yes
#IPV6_PEERDNS=yes
#IPV6_PEERROUTES=yes
#IPV6_FAILURE_FATAL=no
NAME=eth0
#UUID=6c0f1aec-5cad-46d5-b213-572aeffd8c2e
DEVICE=eth0
ONBOOT=yes
#IPADDR=192.168.56.12
#NETMASK=255.255.255.0
GATEWAY=192.168.56.2
BRIDGE=br0
[root@linux-node2 network-scripts]#

3.重启启动（写成脚本）

ifdown br0
ifdown eth0
ifup br0
ifup eth0

如果四步骤结束后还有eth0 的IP 建议重启服务器

4.virt-manager  创建虚拟机 （默认创建了以后键盘会不一样 安装以后调整键盘）

自己创建qcow2  格式的硬盘  用virt-manager 加路径选择    iso镜像也是加绝对路径选择