一.方法一：
在网卡eth1上添加一个虚拟ip 192.168.1.100
1.添加ip
[root@zw-test-db mastermha]#/sbin/ip addr add 192.168.1.100/24 dev eth1
2.查看添加的虚拟ip
[root@zw-test-db mastermha]# 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
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:50:56:a3:6f:08 brd ff:ff:ff:ff:ff:ff
inet 192.168.26.233/24 brd 192.168.26.255 scope global eth1
inet 192.168.26.74/32 scope global eth1 #这个ip就是我刚新加的
inet6 fe80::250:56ff:fea3:6f08/64 scope link
valid_lft forever preferred_lft forever
3.ping一下看新加的虚拟ip能否ping通
[root@zw-test-db mastermha]# ping 192.168.1.100
PING 192.168.1.100(192.168.1.100) 56(84) bytes of data.
64 bytes from 192.168.1.100: icmp_seq=1 ttl=64 time=0.028 ms
4.比如要想删除刚添加的虚拟ip就用如下命令：
[root@zw-test-db mastermha]#/sbin/ip addr del 192.168.1.100/24 dev eth1
5. 为了防止下次重启找不到添加的虚拟ip，可以把命令加到/etc/rc.loca里面
/sbin/ip addr add 192.168.1.100/24 dev eth1
二.方法二：
/etc/sysconfig/ifcfg-xxx 对应的文件中增加配置虚拟IP的方法，可以参见如下：
#cd /etc/sysconfig/network
# vi ifcfg-eth1
BOOTPROTO='static'
BROADCAST=''
ETHTOOL_OPTIONS=''
IPADDR='188.4.1.57/24'
MTU=''
NAME='Ethernet Card 1'
NETWORK=''
REMOTE_IPADDR=''
STARTMODE='manual'
IPADDR_0='188.4.1.56/24'
LABEL_0='1'
