两端都为双主，也同时为对方的备份，主服务器宕机，从服务器自动切换上去，保证主服务器能使用，也不影响从服务器使用

　　一、修改192.168.1.4上keepalived配置文件

vim /etc/keepalived/keepalived.conf

　　1、复制实例1

修改前：

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 88
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.1.100/24 dev ens33 label ens33:1
    }
        notify_master "/etc/keepalived/notify.sh master"
        notify_backup "/etc/keepalived/notify.sh backup"
        notify_fault "/etc/keepalived/notify.sh fault"
}

修改后：

vrrp_instance VI_2{
    state BACKUP
    interface ens33
    virtual_router_id 66
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 654321
    }
    virtual_ipaddress {
        192.168.1.200/24 dev ens33 label ens33:2
    }
        notify_master "/etc/keepalived/notify.sh master"
        notify_backup "/etc/keepalived/notify.sh backup"
        notify_fault "/etc/keepalived/notify.sh fault"
}

　　二、修改192.168.1.8的实例

　　1、复制实例1

修改前：

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 88
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.1.100/24 dev ens33 label ens33:1
    }
        notify_master "/etc/keepalived/notify.sh master"
        notify_backup "/etc/keepalived/notify.sh backup"
        notify_fault "/etc/keepalived/notify.sh fault"
}

修改后：

vrrp_instance VI_2 {
    state MASTER
    interface ens33
    virtual_router_id 66
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 654321
    }
    virtual_ipaddress {
        192.168.1.200/24 dev ens33 label ens33:2
    }
        notify_master "/etc/keepalived/notify.sh master"
        notify_backup "/etc/keepalived/notify.sh backup"
        notify_fault "/etc/keepalived/notify.sh fault"
}

　　三、目前192.168.1.4这台服务器VIP地址是192.168.1.100

ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    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 state UP qlen 1000
    link/ether 00:0c:29:88:cd:f0 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.4/24 brd 192.168.1.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 192.168.1.100/24 scope global secondary ens33:1
       valid_lft forever preferred_lft forever
    inet6 fe80::82fc:253f:d442:8fa4/64 scope link 
       valid_lft forever preferred_lft forever

　　四、目前192.168.1.8的VIP地址192.168.1.200

ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    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 state UP qlen 1000
    link/ether 00:0c:29:62:3f:c8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.8/24 brd 192.168.1.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 192.168.1.200/24 scope global secondary ens33:2
       valid_lft forever preferred_lft forever
    inet6 fe80::ff68:f7e6:3d27:aa58/64 scope link 
       valid_lft forever preferred_lft forever
    inet6 fe80::5585:1cb1:8329:e534/64 scope link tentative dadfailed 
       valid_lft forever preferred_lft forever

　　五、停止192.168.1.8的keepalived服务

systemctl stop keepalived

　　六、查看192.168.1.4的IP地址

ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    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 state UP qlen 1000
    link/ether 00:0c:29:88:cd:f0 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.4/24 brd 192.168.1.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet 192.168.1.100/24 scope global secondary ens33:1
       valid_lft forever preferred_lft forever
    inet 192.168.1.200/24 scope global secondary ens33:2
       valid_lft forever preferred_lft forever
    inet6 fe80::82fc:253f:d442:8fa4/64 scope link 
       valid_lft forever preferred_lft forever