Centos下部署DRBD+NFS+Keepalived高可用环境记录

使用NFS服务器（比如图片业务），一台为主，一台为备。通常主到备的数据同步是通过rsync来做（可以结合inotify做实时同步）。由于NFS服务是存在单点的，出于对业务在线率和数据安全的保障，可以采用"DRBD+NFS+Keepalived"架构来完成高可用方案部署。之前介绍了DRBD详细解说及配置过程记录，废话不多说了，基于之前的那篇文档的机器配置信息，以下记录部署过程：

思路：

1）在两台机器上安装keepalived，VIP为192.168.1.200

2）将DRBD的挂载目录/data作为NFS的挂载目录。远程客户机使用vip地址挂载NFS

3）当Primary主机发生宕机或NFS挂了的故障时，Secondary主机提权升级为DRBD的主节点，并且VIP资源也会转移过来。

   当Primary主机的故障恢复时，会再次变为DRBD的主节点，并重新夺回VIP资源。从而实现故障转移

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Primary和Secondary两台主机的DRBD环境部署，参见https://blog.youkuaiyun.com/RustyChen/article/details/89076650

  

Primary主机（192.168.1.151）默认作为DRBD的主节点，DRBD挂载目录是/data

Secondary主机（192.168.1.152）是DRBD的备份节点

  

在Primary主机上查看DRBD状态，如下，可知Primary主机是DRBD的主节点

[root@Primary ~]# /etc/init.d/drbd status

drbd driver loaded OK; device status:

version: 8.3.16 (api:88/proto:86-97)

GIT-hash: a798fa7e274428a357657fb52f0ecf40192c1985 build by phil@Build64R6, 2014-11-24 14:51:37

m:res  cs         ro                 ds                 p  mounted  fstype

0:r0   Connected  Primary/Secondary  UpToDate/UpToDate  C  /data    ext4

  

如下，DRBD已完成挂载，挂载目录是/data

[root@Primary ~]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup00-LogVol00

                      156G   36G  112G  25% /

tmpfs                 2.9G     0  2.9G   0% /dev/shm

/dev/vda1             190M   98M   83M  55% /boot

/dev/drbd0            9.8G   23M  9.2G   1% /data

  

DRBD数据如下

[root@Primary ~]# cd /data

[root@Primary data]# ll

total 16

-rw-r--r--. 1 root root 9 May 25 09:33 test3

-rw-r--r--. 1 root root 5 May 25 09:34 wangshibo

-rw-r--r--. 1 root root 5 May 25 09:34 wangshibo1

-rw-r--r--. 1 root root 5 May 25 09:34 wangshibo2

  

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在Primary和Secondary两台主机上安装NFS（可以参考：http://www.cnblogs.com/kevingrace/p/6084604.html）

[root@Primary ~]# yum install rpcbind nfs-utils

[root@Primary ~]# vim /etc/exports

/data 192.168.1.0/24(rw,sync,no_root_squash)

  

[root@Primary ~]# /etc/init.d/rpcbind start

[root@Primary ~]# /etc/init.d/nfs start

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关闭两台主机的iptables防火墙

防火墙最好关闭，否则可能导致客户机挂载nfs时会失败！

若开启防火墙，需要在iptables中开放nfs相关端口机以及VRRP组播地址

[root@Primary ~]# /etc/init.d/iptables stop

 

两台机器上的selinux一定要关闭！！！！！！！！！！

否则下面在keepalived.conf里配置的notify_master.sh等脚本执行失败！这是曾经踩过的坑！

[root@Primary ~]# setenforce 0     //临时关闭。永久关闭的话，还需要在/etc/sysconfig/selinux 文件里将SELINUX改为disabled

[root@Primary ~]# getenforce

Permissive

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在两台主机上安装Keepalived，配合keepalived实现自动fail-over

  

安装Keepalived

[root@Primary ~]# yum install -y openssl-devel popt-devel

[root@Primary ~]# cd /usr/local/src/

[root@Primary src]# wget http://www.keepalived.org/software/keepalived-1.3.5.tar.gz

[root@Primary src]# tar -zvxf keepalived-1.3.5.tar.gz

[root@Primary src]# cd keepalived-1.3.5

[root@Primary keepalived-1.3.5]# ./configure --prefix=/usr/local/keepalived

[root@Primary keepalived-1.3.5]# make && make install

        

[root@Primary keepalived-1.3.5]# cp /usr/local/src/keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/rc.d/init.d/

[root@Primary keepalived-1.3.5]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

[root@Primary keepalived-1.3.5]# mkdir /etc/keepalived/

[root@Primary keepalived-1.3.5]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

[root@Primary keepalived-1.3.5]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

[root@Primary keepalived-1.3.5]# echo "/etc/init.d/keepalived start" >> /etc/rc.local

         

[root@Primary keepalived-1.3.5]# chmod +x /etc/rc.d/init.d/keepalived      #添加执行权限

[root@Primary keepalived-1.3.5]# chkconfig keepalived on                   #设置开机启动