LVS IP信息：
主LVS：192.168.1.2
备LVS：192.168.1.3
虚拟IP：192.168.1.6
应用服务器1：192.168.1.12
应用服务器2：192.168.1.13查看内核是否支持LVS模块：
modprobe -l |grep ipvs
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_dh.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_ftp.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_lblc.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_lblcr.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_lc.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_nq.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_rr.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_sed.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_sh.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_wlc.ko
/lib/modules/2.6.18-274.17.1.el5/kernel/net/ipv4/ipvs/ip_vs_wrr.ko根据内核版本下载安装相应的ipvsadm：
ln -s /usr/src/kernels/2.6.18-274.17.1.el5-x86_64/ /usr/src/linux
wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz
tar zxvf ipvsadm-1.24.tar.gz
cd ipvsadm-1.24
make
make install也可使用yum直接安装：
yum install ipvsadm安装Keepalived：
wget http://www.keepalived.org/software/keepalived-1.1.19.tar.gz
tar zxvf keepalived-1.1.19.tar.gz
cd keepalived-1.1.19
./configure --sysconf=/etc/ --with-kernel-dir=/usr/src/kernels/2.6.18-274.17.1.el5-x86_64/
make
make install
ln -s /usr/local/sbin/keepalived /sbin/keepalived主LVS配置keepalived：
! Configuration File for keepalived
global_defs {
notification_email {
admin@www.haiyun.me
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.6
}
}
virtual_server 192.168.1.6 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.1.12 80 {
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.1.13 80 {
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}启动keepalived，同时会在主LVS绑定VIP：
/etc/init.d/keepalived start
ip add show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:0c:29:e7:cc:3b brd ff:ff:ff:ff:ff:ff
inet 192.168.1.3/24 brd 192.168.1.255 scope global eth0
inet 192.168.1.6/32 scope global eth0查看当前LVS参数：
ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.1.6:http rr
-> 192.168.1.12:http Route 1 0 0
-> 192.168.1.13:http Route 1 0 0 复制主keepalived到备LVS，修改以下参数：
state BACKUP
priority 90应用服务器增加虚拟VIP：
#!/bin/bash
VIP=192.168.1.6
. /etc/rc.d/init.d/functions
case "$1" in
start)
ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $SNS
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
sysctl -p >/dev/null 2>&1
echo "RealServer Start OK"
;;
stop)
ifconfig lo:0 down
echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "RealServer Stoped"
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac测试LVS故障切换，停止主LVS上keepalived服务：
/etc/init.d/keepalived stop查看备LVS已经接管为主LVS：
tail -n 10 /var/log/message
Jul 14 20:30:28 centos5 Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE
Jul 14 20:30:29 centos5 Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE
Jul 14 20:30:29 centos5 Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs.
Jul 14 20:30:29 centos5 Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.1.6应用服务器故障测试，停止其中之一httpd服务：
/etc/init.d/httpd stop查看keepalved日志已将出错服务器移除并邮件报警：
tail -n 10 /var/log/message
Jul 14 21:36:18 centos5 Keepalived_healthcheckers: TCP connection to [192.168.1.12:80] failed !!!
Jul 14 21:36:18 centos5 Keepalived_healthcheckers: Removing service [192.168.1.12:80] from VS [192.168.1.6:80]
Jul 14 21:36:18 centos5 Keepalived_healthcheckers: Remote SMTP server [127.0.0.1:25] connected.ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.1.6:http rr
-> 192.168.1.13:http Route 1 0 0