DRBD以其开源，简单，高效，性能不俗为广大运维者们所青睐。主要功能是在不同节点上两个相同大小的设备块级别之间的数据同步镜像。drbd是由内核模块和相关脚本而构成，用以构建高可用性的集群。本文主要描述其安装方式，供大家参考。
有关DRBD的特性，功能及其相关基础知识，大家可以参考： DRBD原理及特性概述
# cp /usr/local/drbd/etc/rc.d/init.d/drbd /etc/init.d/drbd
# chkconfig --add drbd
# chkconfig drbd on1
2、安装drbd模块(两节点)
# cd /usr/local/src/drbd-8.3.15/drbd
# make clean
# make KDIR=/usr/src/kernels/2.6.32-431.el6.x86_64/
# cp drbd.ko /lib/modules/`uname -r`/kernel/lib/
# depmod
# modprobe drbd ###加载drbd模块到Linux内核
注：/usr/src/kernels/2.6.18-274.18.1.el5-i686/这个内核源码树路径需要根据自己的系统修改。
3、验证drbd内核加载(两节点)
# lsmod |grep drbd
drbd 345363 0
# more /usr/local/drbd/etc/drbd.conf ###查看drbd.conf应包含下列include内容
# You can find an example in /usr/share/doc/drbd.../drbd.conf.example
include "drbd.d/global_common.conf";
include "drbd.d/*.res";
# mv /usr/local/drbd/etc/drbd.d/global_common.conf /usr/local/drbd/etc/drbd.d/global_common.conf.bk
# vi /usr/local/drbd/etc/drbd.d/global_common.conf ###global_common.conf可以参考drbd.conf.example
global {
usage-count yes;
# minor-count dialog-refresh disable-ip-verification
}
common {
protocol C;
handlers {
}
startup {
wfc-timeout 0; degr-wfc-timeout 120;
}
disk {
on-io-error detach;
}
net {
# sndbuf-size rcvbuf-size timeout connect-int ping-int ping-timeout max-buffers
# max-epoch-size ko-count allow-two-primaries cram-hmac-alg shared-secret
# after-sb-0pri after-sb-1pri after-sb-2pri data-integrity-alg no-tcp-cork
cram-hmac-alg sha1;
shared-secret "MySQL-HA";
}
syncer {
# rate after al-extents use-rle cpu-mask verify-alg csums-alg
rate 35M;
}
}
###配置资源文件redisk.res
# vi /usr/local/drbd/etc/drbd.d/redisk.res
resource redisk {
on orasrv1.xlk.com {
device /dev/drbd0;
disk /dev/sdb1;
address 192.168.21.10:7789;
meta-disk internal;
}
on orasrv2.xlk.com {
device /dev/drbd0;
disk /dev/sdb1;
address 192.168.21.13:7789;
meta-disk internal;
}
}
###也可以通过copy方式直接将配置文件copy到节点2，则无需单独配置2个配置文件，如下：
# scp /usr/local/drbd/etc/drbd.d/* 192.168.21.13:/usr/local/drbd/etc/drbd.d/
# scp /usr/local/drbd/etc/drbd.conf 192.168.21.13:/usr/local/drbd/etc/
6、创建device metadata(两节点执行)
# drbdadm create-md redisk
Writing meta data...
initializing activity log
NOT initialized bitmap
New drbd meta data block successfully created.
[root@orasrv1 drbd.d]# drbdadm up redisk
[root@orasrv1 drbd.d]# /etc/init.d/drbd status
drbd driver loaded OK; device status:
version: 8.3.15 (api:88/proto:86-97)
GIT-hash: 0ce4d235fc02b5c53c1c52c53433d11a694eab8c build by [email protected], 2015-10-31 09:16:05
m:res cs ro ds p mounted fstype
0:redisk WFConnection Secondary/Unknown Inconsistent/DUnknown C1
5、设置Primary节点(主节点)
以下操作仅在节点1(orasrv1)执行
# drbdadm primary --force redisk
0: State change failed: (-2) Need access to UpToDate data
Command 'drbdsetup 0 primary' terminated with exit code 17
# drbdadm -- --overwrite-data-of-peer primary redisk
# mkfs.ext3 /dev/drbd0
# mkdir /data
# mount /dev/drbd0 /data
# df -h |grep data
/dev/drbd0 2.0G 36M 1.9G 2% /data
###在第二个节点上创建/data目录
# mkdir /data
###查看drbd状态信息：
#cat /proc/drbd
四、DRBD数据镜像功能测试
###首先在主节点完成如下操作
# cp -R /usr/local/drbd /data
# ls /data/drbd
etc lib sbin share var
# du -sh /data/drbd
324K /data/drbd
# umount /data
# drbdadm secondary redisk
# cat /proc/drbd
version: 8.3.15 (api:88/proto:86-97)
GIT-hash: 0ce4d235fc02b5c53c1c52c53433d11a694eab8c build by [email protected], 2015-10-31 10:58:13
0: cs:Connected ro:Secondary/Secondary ds:UpToDate/UpToDate C r-----
ns:1044700 nr:0 dw:33780 dr:1045517 al:3 bm:64 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0
###在备用节点完成如下操作
# drbdadm primary redisk
# cat /proc/drbd
version: 8.3.15 (api:88/proto:86-97)
GIT-hash: 0ce4d235fc02b5c53c1c52c53433d11a694eab8c build by [email protected], 2015-10-31 10:59:26
0: cs:Connected ro:Primary/Secondary ds:UpToDate/UpToDate C r-----
ns:0 nr:1044700 dw:1044700 dr:672 al:0 bm:64 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0
# mount /dev/drbd0 /data
# du -sh /data/drbd ###两节点数据目录及大小完全一致
324K /data/drbd