DRBDを用いたHAクラスタシステム

# rpm -ivh http://www.elrepo.org/elrepo-release-6-6.el6.elrepo.noarch.rpm

# rpm -ivh http://iij.dl.sourceforge.jp/linux-ha/62369/pacemaker-repo-1.1.12-1.1.el6.x86_64.rpm

# vi /etc/yum.repos.d/CentOS-Base.repo
exclude=pacemaker* corosync* heartbeat* resource-agents* cluster-glue* libqb*

# yum install drbd84* kmod-drbd84*

# yum install pacemaker-all

# chkconfig mysqld off
# chkconfig drbd on
# chkconfig corosync on
# chkconfig pacemaker on

include "drbd.d/global_common.conf";
include "drbd.d/*.res";

# vi /etc/drbd.d/r0.res
resource r0 {
     protocol C;
     device /dev/drbd0;
     meta-disk internal;
     on db1 {
          address 10.1.1.1:7788;
          disk /dev/sda4;
     }
     on db2 {
          address 10.1.1.2:7788;
          disk /dev/sda4;
     }
}

# drbdadm create-md r0

# dd if=/dev/zero of=/dev/sda4 bs=512 count=1024
# drbdadm create-md r0

# service drbd start

db1# drbdadm -- --overwrite-data-of-peer primary r0

db1# drbd-overview
（DRBDプライマリ側）
0:r0/0  SyncSource Primary/Secondary UpToDate/Inconsistent /data ext4 990M 1.3M 938M 1%
        [===============>....] sync'ed: 80.1% (209628/1046144)K

db2# drbd-overview
（DRBDセカンダリ側）
0:r0/0  SyncTarget Secondary/Primary Inconsistent/UpToDate
        [===============>....] sync'ed: 82.1% (191356/1046144)K

初期同期完了後のステータス
相手側のステータスが"UpToDate"と表示されます。

（DRBDプライマリ側）
0:r0/0  Connected Primary/Secondary UpToDate/UpToDate /data ext4 990M 1.3M 938M 1%

（DRBDセカンダリ側）
0:r0/0  Connected Secondary/Primary UpToDate/UpToDate

db1# mkfs.ext4 /dev/drbd0

# ls /data

db1# mount /dev/drbd0 /data
db1# df -h

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2       2.0G  1.3G  569M  70% /
tmpfs           499M     0  499M   0% /dev/shm
/dev/sda1       488M   27M  437M   6% /boot
/dev/drbd0      990M   23M  917M   3% /data

db1# mv /var/lib/mysql /data/
db1# ln -s /data/mysql /var/lib/mysql

db2# rm -fr /var/lib/mysql
db2# ln -s /data/mysql /var/lib/

db1# service mysqld start

db1# service mysqld stop

db1# umount /data

db1# drbdadm secondary r0

db2# drbdadm primary r0

db2# mount /dev/drbd0 /data

db2# service mysqld start
mysqld を起動中:　　　　　　[  OK  ]

db2# service mysqld stop

db1# umount /data

# ls /etc/corosync
corosync.conf.example  corosync.conf.example.udpu  uidgid.d

# cd /etc/corosync
# cp -p corosync.conf.example corosync.conf

# vi corosync.conf 
totem { 
　　version: 2 

　　# crypto_cipher and crypto_hash: Used for mutual node authentication. 
　　# If you choose to enable this, then do remember to create a shared 
　　# secret with "corosync-keygen". 
　　# enabling crypto_cipher, requires also enabling of crypto_hash. 
　　crypto_cipher: none 
　　crypto_hash: none 

　　# interface: define at least one interface to communicate 
　　# over. If you define more than one interface stanza, you must 
　　# also set rrp_mode. 
　　interface { 
　　　　# Rings must be consecutively numbered, starting at 0. 
　　　　ringnumber: 0 
　　　　# This is normally the *network* address of the 
　　　　# interface to bind to. This ensures that you can use 
　　　　# identical instances of this configuration file 
　　　　# across all your cluster nodes, without having to 
　　　　# modify this option. 
　　　　bindnetaddr: 10.1.1.0 
　　　　# However, if you have multiple physical network 
　　　　# interfaces configured for the same subnet, then the 
　　　　# network address alone is not sufficient to identify 
　　　　# the interface Corosync should bind to. In that case, 
　　　　# configure the *host* address of the interface 
　　　　# instead: 
　　　　# bindnetaddr: 192.168.1.1 
　　　　# When selecting a multicast address, consider RFC 
　　　　# 2365 (which, among other things, specifies that 
　　　　# 239.255.x.x addresses are left to the discretion of 
　　　　# the network administrator). Do not reuse multicast 
　　　　# addresses across multiple Corosync clusters sharing 
　　　　# the same network. 
　　　　mcastaddr: 239.255.1.1 
　　　　# Corosync uses the port you specify here for UDP 
　　　　# messaging, and also the immediately preceding 
　　　　# port. Thus if you set this to 5405, Corosync sends 
　　　　# messages over UDP ports 5405 and 5404. 
　　　　mcastport: 5405 
　　　　# Time-to-live for cluster communication packets. The 
　　　　# number of hops (routers) that this ring will allow 
　　　　# itself to pass. Note that multicast routing must be 
　　　　# specifically enabled on most network routers. 
　　　　ttl: 1 
　　} 
　　interface { 
　　　　ringnumber: 1 
　　　　bindnetaddr: 10.1.2.0 
　　　　mcastaddr: 239.255.2.1 
　　　　mcastport: 5405 
　　　　ttl: 1 
　　} 
　　rrp_mode: active 
} 
logging { 
　　# Log the source file and line where messages are being 
　　# generated. When in doubt, leave off. Potentially useful for 
　　# debugging. 
　　fileline: off 
　　# Log to standard error. When in doubt, set to no. Useful when 
　　# running in the foreground (when invoking "corosync -f") 
　　to_stderr: no 
　　# Log to a log file. When set to "no", the "logfile" option 
　　# must not be set. 
　　to_logfile: yes 
　　logfile: /var/log/cluster/corosync.log 
　　# Log to the system log daemon. When in doubt, set to yes. 
　　to_syslog: no 
　　# Log debug messages (very verbose). When in doubt, leave off. 
　　debug: off 
　　# Log messages with time stamps. When in doubt, set to on 
　　# (unless you are only logging to syslog, where double 
　　# timestamps can be annoying). 
　　timestamp: on 
　　logger_subsys { 
　　　　subsys: QUORUM 
　　　　debug: off 
　　} 
} 

quorum { 
　　# Enable and configure quorum subsystem (default: off) 
　　# see also corosync.conf.5 and votequorum.5 
　　provider: corosync_votequorum 
　　expected_votes: 2 
} 

nodelist { 
　　node { 
　　　　ring0_addr: 10.1.1.1 
　　　　ring1_addr: 10.1.2.1 
　　　　nodeid: 1 
　　} 
　　node { 
　　　　ring0_addr: 10.1.1.2 
　　　　ring1_addr: 10.1.2.2 
　　　　nodeid: 2 
　　} 
}

# service corosync start
# service pacemaker start

# crm_mon -i1 
Last updated: Wed Sep 9 18:15:19 2015 
Last change: Wed Sep 9 18:14:56 2015 
Stack: corosync 
Current DC: db2 (2) - partition with quorum 
Version: 1.1.12-561c4cf 
2 Nodes configured 
0 Resources configured 

Online: [ db1 db2 ] 

--- 
※[ctrl+c]キーでモニタリングを停止します。

# crm configure
crm(live)configure#

crm(live)configure# property stonith-enabled="false" ¥
no-quorum-policy="ignore"

crm(live)configure# rsc_defaults rsc-options: ¥ 
　　resource-stickiness="INFINITY" ¥ 
　　migration-threshold=1

crm(live)configure# primitive res0_drbd_mysql ocf:linbit:drbd params drbd_resource="r0" ¥ 
  op start interval="0" timeout="240" ¥ 
  op stop interval="0" timeout="120"

crm(live)configure# primitive res0_fs_mysql ocf:heartbeat:Filesystem ¥ 
　　params device="/dev/drbd0" directory="/data" fstype="ext4" ¥ 
　　op start interval="0" timeout="60" ¥ 
　　op stop interval="0" timeout="60" ¥ 
　　op monitor interval="10" timeout="40"

crm(live)configure# primitive res0_vip_mysql ocf:heartbeat:IPaddr2 ¥ 
　　params ip="10.1.0.10" nic="eth0:1" cidr_netmask="24" ¥ 
　　op monitor interval="10" timeout="30"

crm(live)configure# primitive res0_mysqld ocf:heartbeat:mysql ¥ 
　　op start interval="0" timeout="120" ¥ 
　　op stop interval="0" timeout="120" ¥ 
　　op monitor interval="10" timeout="30"

crm(live)configure# group gr0_mysql res0_fs_mysql res0_vip_mysql res0_mysqld

crm(live)configure# ms ms_drbd_mysql res0_drbd_mysql ¥ 
　　meta master-max="1" master-node-max="1" ¥ 
　　clone-max="2" clone-node-max="1" notify="true"

crm(live)configure# colocation mysql_on_drbd inf: gr0_mysql ms_drbd_mysql:Master

crm(live)configure# order mysql_after_drbd inf: ms_drbd_mysql:promote gr0_mysql:start

crm(live)configure# show

crm(live)configure# verify

crm(live)configure# commit

crm(live)configure# exit
bye

# crm_mon
Last updated: Wed Sep 9 18:39:19 2015 
Last change: Wed Sep 9 18:39:17 2015 
Stack: corosync 
Current DC: db2 (2) - partition with quorum 
Version: 1.1.12-561c4cf 
2 Nodes configured 
5 Resources configured 

Online: [ db1 db2 ] 

Resource Group: gr0_mysql 
　　res0_fs_mysql (ocf::heartbeat:Filesystem): Started db1 
　　res0_vip_mysql (ocf::heartbeat:IPaddr2): Started db1 
　　res0_mysqld (ocf::heartbeat:mysql): Started db1 
Master/Slave Set: ms_drbd_mysql [res0_drbd_mysql] 
　　Masters: [ db1 ] 
　　Slaves: [ db2 ]

# crm_mon -i1 
Online: [ db1 db2 ] 

Resource Group: gr0_mysql 
　　res0_fs_mysql (ocf::heartbeat:Filesystem): Started db1 
　　res0_vip_mysql (ocf::heartbeat:IPaddr2): Started db1 
　　res0_mysqld (ocf::heartbeat:mysql): Started db1 
Master/Slave Set: ms_drbd_mysql [res0_drbd_mysql] 
　　Masters: [ db1 ] 
　　Slaves: [ db2 ]

# crm node standby db1

# crm_mon -i1 
Node db1 (1): standby 
Online: [ db2 ] 

Resource Group: gr0_mysql 
　　res0_fs_mysql (ocf::heartbeat:Filesystem): Started db2 
　　res0_vip_mysql (ocf::heartbeat:IPaddr2): Started db2 
　　res0_mysqld (ocf::heartbeat:mysql): Started db2 
Master/Slave Set: ms_drbd_mysql [res0_drbd_mysql] 
　　Masters: [ db2 ] 
　　Stopped: [ db1 ]

# crm node online db1 

Online: [ db1 db2 ] 

Resource Group: gr0_mysql 
　　res0_fs_mysql (ocf::heartbeat:Filesystem): Started db2 
　　res0_vip_mysql (ocf::heartbeat:IPaddr2): Started db2 
　　res0_mysqld (ocf::heartbeat:mysql): Started db2 
Master/Slave Set: ms_drbd_mysql [res0_drbd_mysql] 
　　Masters: [ db2 ] 
　　Slaves: [ db1 ]