linux新增虛擬ip（手動vip和keepalived方式）
1，手動新增vip
1,ifconfig檢視當前活動網絡卡。如：eth0
2,執行
ifconfig eth0:0 166.111.69.100 netmask 255.255.255.0 up
進行vip新增
3，執行ifconfig檢視是否生效
4，測試 ping 166.111.69.100
5,寫在/etc/rc.local裡進行開機自動設定
2，第三方工具keepalived增加vip
1，下載與安裝
下載：http://download.csdn.net/detail/u014749692/8396867
安裝：
tar xf keepalived-1.2.12.tar.gz cd keepalived-1.2.12 ./configure --prefix=/usr/local/keepalived make && make install cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/ cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ mkdir /etc/keepalived cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
2，配置：
vim
/etc/keepalived/keepalived.conf 如下：
! Configuration File for keepalived
global_defs { notification_email { [email protected] } notification_email_from [email protected] smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MySQL-HA }
vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 51 priority 150 advert_int 1 nopreempt
authentication { auth_type PASS auth_pass 1111 }
virtual_ipaddress { 192.168.0.88 } }
紅色區域為需要修改的地方：
notification_email :變更後通知的email
notification_email_from :傳送email
router_id MySQL-HA :路由器組id，區域網中需要共享該vip的伺服器，該配置要一致。
state BACKUP：在keepalived中2種模式，分別是master->backup模式和backup->backup模式。這兩種模式有很大區別。在master->backup模式下，一旦主庫宕機，虛擬ip會自動漂移到從庫，當主庫修復後，keepalived啟動後，還會把虛擬ip搶佔過來，即使設定了非搶佔模式（nopreempt）搶佔ip的動作也會發生。在backup->backup模式下，當主庫宕機後虛擬ip會自動漂移到從庫上，當原主庫恢復和keepalived服務啟動後，並不會搶佔新主的虛擬ip，即使是優先順序高於從庫的優先級別，也不會發生搶佔。
interface eth1:具體網絡卡，通過ifconfig確認具體網絡卡。
priority 150:表示設定的優先順序為150
nopreempt:非搶佔模式
啟動：
/etc/init.d/keepalived start ; tail -f /var/log/messages
顯示如下表示成功：
Starting keepalived: [ OK ] Apr 20 20:26:18 192 Keepalived_vrrp[9472]: Registering gratuitous ARP shared channel Apr 20 20:26:18 192 Keepalived_vrrp[9472]: Opening file '/etc/keepalived/keepalived.conf'. Apr 20 20:26:18 192 Keepalived_vrrp[9472]: Configuration is using : 62976 Bytes Apr 20 20:26:18 192 Keepalived_vrrp[9472]: Using LinkWatch kernel netlink reflector... Apr 20 20:26:18 192 Keepalived_vrrp[9472]: VRRP_Instance(VI_1) Entering BACKUP STATE Apr 20 20:26:18 192 Keepalived_vrrp[9472]: VRRP sockpool: [ifindex(3), proto(112), unicast(0), fd(10,11)] Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Netlink reflector reports IP 192.168.80.138 added Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Netlink reflector reports IP 192.168.0.60 added Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Netlink reflector reports IP fe80::20c:29ff:fe9d:6a9e added Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Netlink reflector reports IP fe80::20c:29ff:fe9d:6aa8 added Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Registering Kernel netlink reflector Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Registering Kernel netlink command channel Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Opening file '/etc/keepalived/keepalived.conf'. Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Configuration is using : 7231 Bytes Apr 20 20:26:18 192 kernel: IPVS: Registered protocols (TCP, UDP, AH, ESP) Apr 20 20:26:18 192 kernel: IPVS: Connection hash table configured (size=4096, memory=64Kbytes) Apr 20 20:26:18 192 kernel: IPVS: ipvs loaded. Apr 20 20:26:18 192 Keepalived_healthcheckers[9471]: Using LinkWatch kernel netlink reflector...
測試：
1，ping命令測試。
2，一臺伺服器停止keepalived服務進行ip漂移測試。
如果失敗，請考慮防火牆原因，參考url： http://blog.chinaunix.net/uid-20794884-id-5704461.html