使用NFS服務器(好比圖片業務),一臺爲主,一臺爲備。一般主到備的數據同步是經過rsync來作(能夠結合inotify作實時同步)。因爲NFS服務是存在單點的,出於對業務在線率和數據安全的保障,能夠採用"DRBD+NFS+Keepalived"架構來完成高可用方案部署。以前介紹了DRBD詳細解說及配置過程記錄,廢話很少說了,基於以前的那篇文檔的機器配置信息,如下記錄部署過程:html
思路: 1)在兩臺機器上安裝keepalived,VIP爲192.168.1.200 2)將DRBD的掛載目錄/data做爲NFS的掛載目錄。遠程客戶機使用vip地址掛載NFS 3)當Primary主機發生宕機或NFS掛了的故障時,Secondary主機提權升級爲DRBD的主節點,而且VIP資源也會轉移過來。 當Primary主機的故障恢復時,會再次變爲DRBD的主節點,並從新奪回VIP資源。從而實現故障轉移 ----------------------------------------------------------------------------------------------------------- Primary和Secondary兩臺主機的DRBD環境部署,參見http://www.cnblogs.com/kevingrace/p/5740940.html Primary主機(192.168.1.151)默認做爲DRBD的主節點,DRBD掛載目錄是/data Secondary主機(192.168.1.152)是DRBD的備份節點 在Primary主機上查看DRBD狀態,以下,可知Primary主機是DRBD的主節點 [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 以下,DRBD已完成掛載,掛載目錄是/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數據以下 [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 ----------------------------------------------------------------------------------------------------------- 在Primary和Secondary兩臺主機上安裝NFS(能夠參考: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 --------------------------------------------------------------------------------------------------------- 關閉兩臺主機的iptables防火牆 防火牆最好關閉,不然可能致使客戶機掛載nfs時會失敗! 若開啓防火牆,須要在iptables中開放nfs相關端口機以及VRRP組播地址 [root@Primary ~]# /etc/init.d/iptables stop 兩臺機器上的selinux必定要關閉!!!!!!!!!! 不然下面在keepalived.conf裏配置的notify_master.sh等腳本執行失敗!這是曾經踩過的坑! [root@Primary ~]# setenforce 0 //臨時關閉。永久關閉的話,還須要在/etc/sysconfig/selinux 文件裏將SELINUX改成disabled [root@Primary ~]# getenforce Permissive ----------------------------------------------------------------------------------------------------------- 在兩臺主機上安裝Keepalived,配合keepalived實現自動fail-over 安裝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 #添加執行權限 [root@Primary keepalived-1.3.5]# chkconfig keepalived on #設置開機啓動 [root@Primary keepalived-1.3.5]# service keepalived start #啓動 [root@Primary keepalived-1.3.5]# service keepalived stop #關閉 [root@Primary keepalived-1.3.5]# service keepalived restart #重啓 -----------Primary主機的keepalived.conf配置 [root@Primary ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf-bak [root@Primary ~]# vim /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { root@localhost } notification_email_from keepalived@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id DRBD_HA_MASTER } vrrp_script chk_nfs { script "/etc/keepalived/check_nfs.sh" interval 5 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { chk_nfs } notify_stop /etc/keepalived/notify_stop.sh notify_master /etc/keepalived/notify_master.sh virtual_ipaddress { 192.168.1.200 } } 啓動keepalived服務 [root@Primary data]# /etc/init.d/keepalived start Starting keepalived: [ OK ] [root@Primary data]# ps -ef|grep keepalived root 30937 1 0 11:49 ? 00:00:00 keepalived -D root 30939 30937 0 11:49 ? 00:00:00 keepalived -D root 30940 30937 0 11:49 ? 00:00:00 keepalived -D root 31123 10364 0 11:50 pts/1 00:00:00 grep --color keepalived 查看VIP [root@Primary data]# 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether fa:16:3e:35:d1:d6 brd ff:ff:ff:ff:ff:ff inet 192.168.1.151/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.200/32 scope global eth0 inet6 fe80::f816:3eff:fe35:d1d6/64 scope link valid_lft forever preferred_lft forever -----------Secondary主機的keepalived.conf配置 [root@Secondary ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf-bak [root@Secondary ~]# vim /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { root@localhost } notification_email_from keepalived@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id DRBD_HA_BACKUP } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 90 advert_int 1 authentication { auth_type PASS auth_pass 1111 } notify_master /etc/keepalived/notify_master.sh //當此機器爲keepalived的master角色時執行這個腳本 notify_backup /etc/keepalived/notify_backup.sh //當此機器爲keepalived的backup角色時執行這個腳本 virtual_ipaddress { 192.168.1.200 } } 啓動keepalived服務 [root@Secondary ~]# /etc/init.d/keepalived start Starting keepalived: [ OK ] [root@Secondary ~]# ps -ef|grep keepalived root 17128 1 0 11:50 ? 00:00:00 keepalived -D root 17129 17128 0 11:50 ? 00:00:00 keepalived -D root 17131 17128 0 11:50 ? 00:00:00 keepalived -D root 17219 29939 0 11:50 pts/1 00:00:00 grep --color keepalived -------------四個腳本配置--------------- 1)此腳本只在Primary機器上配置 [root@Primary ~]# vim /etc/keepalived/check_nfs.sh #!/bin/sh ###檢查nfs可用性:進程和是否可以掛載 /sbin/service nfs status &>/dev/null if [ $? -ne 0 ];then ###若是服務狀態不正常,先嚐試重啓服務 /sbin/service nfs restart /sbin/service nfs status &>/dev/null if [ $? -ne 0 ];then ###若重啓nfs服務後,仍不正常 ###卸載drbd設備 umount /dev/drbd0 ###將drbd主降級爲備 drbdadm secondary r0 #關閉keepalived /sbin/service keepalived stop fi fi [root@Primary ~]# chmod 755 /etc/keepalived/check_nfs.sh 2)此腳本只在Primary機器上配置 [root@Primary ~]# mkdir /etc/keepalived/logs [root@Primary ~]# vim /etc/keepalived/notify_stop.sh #!/bin/bash time=`date "+%F %H:%M:%S"` echo -e "$time ------notify_stop------\n" >> /etc/keepalived/logs/notify_stop.log /sbin/service nfs stop &>> /etc/keepalived/logs/notify_stop.log /bin/umount /data &>> /etc/keepalived/logs/notify_stop.log /sbin/drbdadm secondary r0 &>> /etc/keepalived/logs/notify_stop.log echo -e "\n" >> /etc/keepalived/logs/notify_stop.log [root@Primary ~]# chmod 755 /etc/keepalived/notify_stop.sh 3)此腳本在兩臺機器上都要配置 [root@Primary ~]# vim /etc/keepalived/notify_master.sh #!/bin/bash time=`date "+%F %H:%M:%S"` echo -e "$time ------notify_master------\n" >> /etc/keepalived/logs/notify_master.log /sbin/drbdadm primary r0 &>> /etc/keepalived/logs/notify_master.log /bin/mount /dev/drbd0 /data &>> /etc/keepalived/logs/notify_master.log /sbin/service nfs restart &>> /etc/keepalived/logs/notify_master.log echo -e "\n" >> /etc/keepalived/logs/notify_master.log [root@Primary ~]# chmod 755 /etc/keepalived/notify_master.sh 4)此腳本只在Secondary機器上配置 [root@Secondary ~]# mkdir /etc/keepalived/logs [root@Secondary ~]# vim /etc/keepalived/notify_backup.sh #!/bin/bash time=`date "+%F %H:%M:%S"` echo -e "$time ------notify_backup------\n" >> /etc/keepalived/logs/notify_backup.log /sbin/service nfs stop &>> /etc/keepalived/logs/notify_backup.log /bin/umount /dev/drbd0 &>> /etc/keepalived/logs/notify_backup.log /sbin/drbdadm secondary r0 &>> /etc/keepalived/logs/notify_backup.log echo -e "\n" >> /etc/keepalived/logs/notify_backup.log [root@Secondary ~]# chmod 755 /etc/keepalived/notify_backup.sh ----------------------------------------------------------------------------------------------------------- 在遠程客戶機上掛載NFS 客戶端只須要安裝rpcbind程序,並確認服務正常 [root@huanqiu ~]# yum install rpcbind nfs-utils [root@huanqiu ~]# /etc/init.d/rpcbind start 掛載NFS [root@huanqiu ~]# mount -t nfs 192.168.1.200:/data /web 以下查看,發現已經成功掛載了NFS [root@huanqiu ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup00-LogVol00 107G 15G 87G 14% / tmpfs 2.9G 0 2.9G 0% /dev/shm /dev/vda1 190M 67M 113M 38% /boot 192.168.1.200:/data 9.8G 23M 9.2G 1% /web [root@huanqiu ~]# cd /web/ [root@huanqiu web]# 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 ----------------------------------------------------------------------------------------------------------- 接着進行fail-over(故障)自動切換測試: 1) 先關閉Primary主機上的keepalived服務。就會發現VIP資源已經轉移到Secondary主機上了。 同時,Primary主機的nfs也會主動關閉,同時Secondary會升級爲DRBD的主節點 [root@Primary ~]# /etc/init.d/keepalived stop Stopping keepalived: [ OK ] [root@Primary ~]# 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether fa:16:3e:35:d1:d6 brd ff:ff:ff:ff:ff:ff inet 192.168.1.151/24 brd 192.168.1.255 scope global eth0 inet6 fe80::f816:3eff:fe35:d1d6/64 scope link valid_lft forever preferred_lft forever 查看系統日誌,也能看到VIP資源轉移信息 [root@Primary ~]# tail -1000 /var/log/messages ........ May 25 11:50:03 localhost Keepalived_vrrp[30940]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:50:03 localhost Keepalived_vrrp[30940]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:50:03 localhost Keepalived_vrrp[30940]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:50:03 localhost Keepalived_vrrp[30940]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:58:51 localhost Keepalived[30937]: Stopping May 25 11:58:51 localhost Keepalived_vrrp[30940]: VRRP_Instance(VI_1) sent 0 priority May 25 11:58:51 localhost Keepalived_vrrp[30940]: VRRP_Instance(VI_1) removing protocol VIPs. [root@Primary ~]# ps -ef|grep nfs root 588 10364 0 12:13 pts/1 00:00:00 grep --color nfs [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 [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 Secondary/Secondary UpToDate/UpToDate C 登陸到Secondary備份機器上,發現VIP資源已經轉移過來 [root@Secondary ~]# 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether fa:16:3e:4c:7e:88 brd ff:ff:ff:ff:ff:ff inet 192.168.1.152/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.200/32 scope global eth0 inet6 fe80::f816:3eff:fe4c:7e88/64 scope link valid_lft forever preferred_lft forever [root@Secondary ~]# tail -1000 /var/log/messages ........ May 25 11:58:53 localhost Keepalived_vrrp[17131]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:58:53 localhost Keepalived_vrrp[17131]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:58:53 localhost Keepalived_vrrp[17131]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:58:53 localhost Keepalived_vrrp[17131]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:58:58 localhost Keepalived_vrrp[17131]: Sending gratuitous ARP on eth0 for 192.168.1.200 May 25 11:58:58 localhost Keepalived_vrrp[17131]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 192.168.1.200 [root@Secondary ~]# 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether fa:16:3e:4c:7e:88 brd ff:ff:ff:ff:ff:ff inet 192.168.1.152/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.200/32 scope global eth0 inet6 fe80::f816:3eff:fe4c:7e88/64 scope link valid_lft forever preferred_lft forever [root@Secondary ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup00-LogVol00 156G 13G 135G 9% / tmpfs 2.9G 0 2.9G 0% /dev/shm /dev/vda1 190M 89M 92M 50% /boot /dev/drbd0 9.8G 23M 9.2G 1% /data 當Primary機器的keepalived服務恢復啓動後,VIP資源又會強制奪回來(能夠查看/var/log/message系統日誌) 而且Primary還會再次變爲DRBD的主節點 2) 關閉Primary主機的nfs服務。根據監控腳本,會主動去啓動nfs,只要當啓動失敗時,纔會強制由DRBD的主節點降爲備份節點,並關閉keepalived。 從而跟上面流程同樣實現故障轉移 結論: 在上面的主從故障切換過程當中,對於客戶端來講,掛載NFS不影響使用,只是會有一點的延遲。 這也驗證了drbd提供的數據一致性功能(包括文件的打開和修改狀態等),在客戶端看來,真個切換過程就是"一次nfs重啓"(主nfs停,備nfs啓)。