Centos6下DRBD的安装配置

导读	Distributed Replicated Block Device(DRBD)是一个用软件实现的、无共享的、服务器之间镜像块设备内容的存储复制解决方案。数据镜像：实时、透明、同步（所有服务器都成功后返回）、异步（本地服务器成功后返回）。DRBD的核心功能通过Linux的内核实现，最接近系统的IO栈，但它不能神奇地添加上层的功能比如检测到EXT3文件系统的崩溃。DRBD的位置处于文件系统以下，比文件系统更加靠近操作系统内核及IO栈。

一、安装环境说明

系统版本：CentOS6.5

DRBD版本：DRBD-8.4.3

node1:   192.168.7.88（drbd1)
node2:   192.168.7.89 (drbd2)

(node1)为仅主节点配置
(node2)为仅从节点配置
(node1,node2)为主从节点共同配置

二、准备环境：(node1,node2)

1.关闭iptables和SELINUX，避免安装过程中报错

service iptables stop                       //关闭iptables
setenforcing 0                                 //暂时关闭selinux
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/sysconfig/selinux      //永久关闭selinux

2.设置hosts文件

vi /etc/hosts

127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.7.88    drbd1
192.168.7.89    drbd2

3.在两台虚拟机上添加一块2G硬盘sdb作为DRBD，分别分区为sdb1，大小1G，并在本地系统创建/data目录，不做挂载操作。

fdisk /dev/sdb

----------------

n-p-1-回车-"+1G"-wq

----------------

mkdir /data

4.时间同步：

ntpdate -u asia.pool.ntp.org

三、DRBD的安装部署

1.安装依赖包：(node1,node2)

yum install gcc gcc-c++ make glibc flex kernel-devel kernel-headers

2.安装DRBD：(node1,node2)

wget http://oss.linbit.com/drbd/8.4/drbd-8.4.3.tar.gz

tar zxvf drbd-8.4.3.tar.gz

cd drbd-8.4.3

./configure --prefix=/usr/local/drbd --with-km

make && make install

mkdir -p /usr/local/drbd/var/run/drbd

cp /usr/local/drbd/etc/rc.d/init.d/drbd /etc/rc.d/init.d

chkconfig --add drbd

chkconfig drbd on

加载DRBD模块:

modprobe drbd

查看DRBD模块是否加载到内核：

lsmod |grep drbd

四、DRBD的配置

1.参数配置：(node1,node2)

vim /usr/local/drbd/etc/drbd.conf
清空里面的配置，添加如下配置：
resource r0{
protocol C;
startup { wfc-timeout 0; degr-wfc-timeout 120;}
disk { on-io-error detach;}
net{
  timeout 60;
  connect-int 10;
  ping-int 10;
  max-buffers 2048;
  max-epoch-size 2048;
}
syncer { rate 30M;}
on drbd1.example.com{
  device /dev/drbd0;
  disk   /dev/sdb1;
  address 192.168.7.88:7788;
  meta-disk internal;
}
on drbd2.example.com{
  device /dev/drbd0;
  disk   /dev/sdb1;
  address 192.168.7.89:7788;
  meta-disk internal;
}
}

2.创建DRBD设备并激活r0资源：(node1,node2)

mknod /dev/drbd0 b 147 0

drbdadm create-md r0

等待片刻，显示success表示drbd块创建成功
----------------
Writing meta data...
initializing activity log
NOT initializing bitmap
New drbd meta data block successfully created.
               --== Creating metadata ==--
As with nodes, we count the total number of devices mirrored by DRBD
at http://usage.drbd.org.
The counter works anonymously. It creates a random number to identify
the device and sends that random number, along with the kernel and
DRBD version, to usage.drbd.org.
http://usage.drbd.org/cgi-bin/insert_usage.pl?
nu=716310175600466686&ru=15741444353112217792&rs=1085704704
* If you wish to opt out entirely, simply enter 'no'.
* To continue, just press [RETURN]        //出现[RETURN]按回车
success
----------------
再次输入该命令：
# drbdadm create-md r0
成功激活r0
----------------
[need to type 'yes' to confirm] yes
Writing meta data...
initializing activity log
NOT initializing bitmap
New drbd meta data block successfully created.

3.启动DRBD服务：(node1,node2)

service drbd start

注：需要主从共同启动方能生效

4.查看状态：(node1,node2)

cat /proc/drbd

version: 8.4.3 (api:1/proto:86-101)
GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.example.com,
2013-05-27 20:45:19
0: cs:Connected ro:Secondary/Secondary ds:Inconsistent/Inconsistent C r-----
   ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:1060184

或者

service drbd status

drbd driver loaded OK; device status:
version: 8.4.3 (api:1/proto:86-101)
GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.example.com,
2013-05-27 20:45:19
m:res  cs         ro                   ds                         p  mounted  fstype
0:r0   Connected  Secondary/Secondary  Inconsistent/Inconsistent  C

注：这里ro:Secondary/Secondary表示两台主机的状态都是备机状态，ds是磁盘状态，显示的状态内容为“不一致”，这是因为DRBD无法判断哪一方为主机，应以哪一方的磁盘数据作为标准。

5.将drbd1主机配置为主节点：(node1)

drbdsetup /dev/drbd0 primary --force

分别查看主从DRBD状态：

(node1)

service drbd status

drbd driver loaded OK; device status:
version: 8.4.3 (api:1/proto:86-101)
GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.example.com,
2013-05-27 20:45:19
m:res  cs         ro                 ds                 p  mounted  fstype
0:r0   Connected  Primary/Secondary  UpToDate/UpToDate  C

(node2)

service drbd status

drbd driver loaded OK; device status:
version: 8.4.3 (api:1/proto:86-101)
GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd2.example.com,
2013-05-27 20:49:06
m:res  cs         ro                 ds                 p  mounted  fstype
0:r0   Connected  Secondary/PrimaryUpToDate/UpToDate  C

注：ro在主从服务器上分别显示 Primary/Secondary和Secondary/Primary ds显示UpToDate/UpToDate表示主从配置成功。

6.挂载DRBD：(node1)

从刚才的状态上看到mounted和fstype参数为空，所以我们这步开始挂载DRBD到系统目录

mkfs.ext4 /dev/drbd0

mount /dev/drbd0 /data

注：Secondary节点上不允许对DRBD设备进行任何操作，包括只读，所有的读写操作只能
在Primary节点上进行，只有当Primary节点挂掉时，Secondary节点才能提升为Primary节点继续工作。

五、模拟故障

(node1)

cd /data
touch 1 2 3 4 5
cd ..
umount /data
drbdsetup /dev/drbd0 secondary

注：这里实际生产环境若DRBD1宕机，在DRBD2状态信息中ro的值会显示为Secondary/Unknown,只需要进行DRBD提权操作即可。 (node2)

drbdsetup /dev/drbd0 primary
mount  /dev/drbd0 /data
cd /data
touch 6 7 8 9 10
ls
--------------
1  10  2  3  4  5  6  7  8  9  lost+found

查看(node1)(node2)DRBD状态：

(node2)
service drbd status

drbd driver loaded OK; device status:
version: 8.4.3 (api:1/proto:86-101)
GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd2.example.com,
2013-05-27 20:49:06
m:res  cs         ro                 ds                 p  mounted  fstype
0:r0   Connected  Primary/Secondary  UpToDate/UpToDate  C  /data    ext4


(node1)
service drbd status

drbd driver loaded OK; device status:
version: 8.4.3 (api:1/proto:86-101)
GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.example.com,
2013-05-27 20:45:19
m:res  cs         ro                 ds                 p  mounted  fstype
0:r0   Connected  Secondary/Primary  UpToDate/UpToDate  C

本文转载自：https://www.linuxprobe.com/centos6-drdb-setup-instal.html