DRBD配置
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。
我们可以理解为它其实就是个网络Raid 1，两台服务器间就算某台因断电或宕机也不会对数据有任何影响，而真正的热切换可以通过Heartbeat方案解决，不需要人工干预。
一、环境描述
系统版本：centos6.6 x64(内核2.6.32-504.16.2.el6.x86_64)
DRBD版本：DRBD-8.4.3
node1(主节点)IP: 192.168.0.191 主机名：drbd1.corp.com
node2(从节点)IP: 192.168.0.192 主机名：drbd2.corp.com
(node1) 仅为主节点配置
(node2) 仅为从节点配置
(node1,node2) 为主从节点共同配置
二、安装前准备：(node1,node2)
1、关闭iptables和SELINUX，避免安装过程中报错。
1234567 | # service iptables stop# chkconfig iptables off# setenforce 0# vi /etc/selinux/config---------------SELINUX=disabled--------------- |
2、配置hosts文件
123 | # vi /etc/hosts192.168.0.191 drbd1.corp.com192.168.0.191 drbd2.corp.com |
3、在两台虚拟机分别添加一块10G硬盘分区作为DRBD设备磁盘，分别都为sdb1，大小10G，并在本地系统创建/store目录，不做挂载操作。
12345 | # fdisk /dev/sdb----------------n-p-1-1-"+10G"-w----------------# mkdir /store |
4、时间同步：
1 | # ntpdate -u asia.pool.ntp.org |
三、DRBD的安装配置：
1、安装依赖包：(node1,node2)
1 | # yum install gcc gcc-c++ make glibc flex kernel-devel kernel-headers |
2、安装DRBD：(node1,node2)
12345678910 | # 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 KDIR=/usr/src/kernels/2.6.32-504.16.2.el6.x86_64/# 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 |
3、加载DRBD模块:(node1,node2)
1 | # modprobe drbd |
查看DRBD模块是否加载到内核：
123 | # lsmod |grep drbddrbd 310172 4libcrc32c 1246 1 drbd |
4、参数配置：(node1,node2)
1 | # vi /usr/local/drbd/etc/drbd.conf |
清空文件内容，并添加如下配置：
123456789101112131415161718192021222324252627 | 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 200M;} on drbd1.corp.com{device /dev/drbd0;disk /dev/sdb1;address 192.168.0.191:7788;meta-disk internal;}on drbd2.corp.com{device /dev/drbd0;disk /dev/sdb1;address 192.168.0.192:7788;meta-disk internal;}} |
注：请修改上面配置中的主机名、IP、和disk为自己的具体配置
5、创建DRBD设备并激活r0资源：(node1,node2)
12345678910111213141516171819202122232425 | # 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 logNOT initializing bitmapNew drbd meta data block successfully created. --== Creating metadata ==--As with nodes, we count the total number of devices mirrored by DRBDat http://usage.drbd.org. The counter works anonymously. It creates a random number to identifythe device and sends that random number, along with the kernel andDRBD 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] success |
再次输入该命令：
12345678 | # drbdadm create-md r0成功激活r0[need to type 'yes' to confirm] yes Writing meta data...initializing activity logNOT initializing bitmapNew drbd meta data block successfully created. |
6、启动DRBD服务：(node1,node2)
1 | # service drbd start |
注：需要主从共同启动方能生效
7、查看状态：(node1,node2)
123456 | # service drbd statusdrbd driver loaded OK; device status:version: 8.4.3 (api:1/proto:86-101)GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.corp.com, 2015-05-12 21:05:41m:res cs ro ds p mounted fstype0:r0 Connected Secondary/Secondary Inconsistent/Inconsistent C |
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“Inconsistent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。
8、将drbd1.example.com主机配置为主节点：(node1)
1 | # drbdsetup /dev/drbd0 primary --force |
分别查看主从DRBD状态：
(node1)
123456 | # service drbd statusdrbd driver loaded OK; device status:version: 8.4.3 (api:1/proto:86-101)GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.corp.com, 2015-05-12 21:05:41m:res cs ro ds p mounted fstype0:r0 Connected Primary/Secondary UpToDate/UpToDate C |
(node2)
123456 | # service drbd statusdrbd driver loaded OK; device status:version: 8.4.3 (api:1/proto:86-101)GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd2.corp.com, 2015-05-12 21:05:46m:res cs ro ds p mounted fstype0:r0 Connected Secondary/Primary UpToDate/UpToDate C |
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。
9、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/store
12 | # mkfs.ext4 /dev/drbd0# mount /dev/drbd0 /store |
注：Secondary节点上不允许对DRBD设备进行任何操作，包括挂载；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，并自动挂载DRBD继续工作。
成功挂载后的DRBD状态：(node1)
123456 | # service drbd statusdrbd driver loaded OK; device status:version: 8.4.3 (api:1/proto:86-101)GIT-hash: 89a294209144b68adb3ee85a73221f964d3ee515 build by root@drbd1.corp.com, 2015-05-12 21:05:41m:res cs ro ds p mounted fstype0:r0 Connected Primary/Secondary UpToDate/UpToDate C /store ext4 |
