{"id":1096,"date":"2012-08-23T12:23:14","date_gmt":"2012-08-23T04:23:14","guid":{"rendered":"http:\/\/rmohan.com\/?p=1096"},"modified":"2012-08-23T12:23:14","modified_gmt":"2012-08-23T04:23:14","slug":"centos-6-drbd-how-to-set-up-drbd","status":"publish","type":"post","link":"https:\/\/mohan.sg\/?p=1096","title":{"rendered":"CentOS 6 DRBD : how to set up DRBD"},"content":{"rendered":"

 <\/p>\n

Here is an explanation of how to set up DRBD on CentOS6.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
# cat \/etc\/redhat-release<\/div>\n
CentOS release 6.2 (Final)<\/div>\n

<\/p>\n

# uname -ri<\/div>\n
2.6.32-220.7.1.el6.i686 i386<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
# rpm -qa | grep drbd<\/div>\n
kmod-drbd84-8.4.1-1.el6.elrepo.i686<\/div>\n
drbd84-utils-8.4.1-1.el6.elrepo.i686<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Hostname ( uname \u2013n ) of DBRD nodes are:<\/div>\n
centos6-drbd1.localdomain<\/div>\n
centos6-drbd2.localdomain<\/div>\n

 <\/p>\n

These nodes are running as VMs on a KVM host machine ( Linux Mint 12 )<\/div>\n

 <\/p>\n

[ install DRBD on CentOS 6 ]<\/div>\n

 <\/p>\n

CentOS 6 doesn\u2019t seem to have DRBD repo.<\/div>\n

 <\/p>\n

add the DRBD repo<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# rpm -Uvh http:\/\/elrepo.org\/elrepo-release-6-4.el6.elrepo.noarch.rpm<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
edit the DRBD repo.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# vi \/etc\/yum.repos.d\/elrepo.repo<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[elrepo]<\/div>\n
name=ELRepo.org Community Enterprise Linux Repository – el6<\/div>\n
baseurl=http:\/\/elrepo.org\/linux\/elrepo\/el6\/$basearch\/<\/div>\n
mirrorlist=http:\/\/elrepo.org\/mirrors-elrepo.el6<\/div>\n
#enabled=1<\/div>\n
enabled=0<\/div>\n
gpgcheck=1<\/div>\n
gpgkey=file:\/\/\/etc\/pki\/rpm-gpg\/RPM-GPG-KEY-elrepo.org<\/div>\n
protect=0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
confirm you can search DRBD packages via yum<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# yum –enablerepo=elrepo search drbd<\/div>\n
Loaded plugins: fastestmirror, refresh-packagekit<\/div>\n
Loading mirror speeds from cached hostfile<\/div>\n
* base: www.ftp.ne.jp<\/div>\n
* elrepo: elrepo.org<\/div>\n
* extras: www.ftp.ne.jp<\/div>\n
* updates: www.ftp.ne.jp<\/div>\n
elrepo \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| 1.9 kB \u00a0\u00a0\u00a0\u00a000:00<\/div>\n
elrepo\/primary_db \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| 409 kB \u00a0\u00a0\u00a0\u00a000:01<\/div>\n
============================== N\/S Matched: drbd ===============================<\/div>\n
drbd83-utils.i686 : Management utilities for DRBD %{version}<\/div>\n
drbd84-utils.i686 : Management utilities for DRBD<\/div>\n
kmod-drbd83.i686 : drbd83 kernel module(s)<\/div>\n
kmod-drbd84.i686 : drbd84 kernel module(s)<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
install drbd<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# yum –enablerepo=elrepo install \u2013y drbd84-utils.i686 kmod-d<\/div>\n
rbd84.i686<\/div>\n

<\/p>\n

<snip><\/div>\n
Installed:<\/div>\n
\u00a0drbd84-utils.i686 0:8.4.1-1.el6.elrepo \u00a0kmod-drbd84.i686 0:8.4.1-1.el6.elrepo<\/div>\n

<\/p>\n

Complete!<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
do the same things on the other machine<\/div>\n

 <\/p>\n

[ when not using LVM ]<\/div>\n

 <\/p>\n

Before setting up DRBD , I\u2019m going to add a storage for DRBD to both machines which are running on KVM.<\/div>\n

 <\/p>\n

– create a storage with kvm-image for DRBD nodes<\/div>\n

 <\/p>\n

for centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
mint-1 images # qemu-img create -f qcow2 \/var\/disk1\/libvirt\/images\/centos6-drbd1
-1.img 500M
Formatting ‘\/var\/disk1\/libvirt\/images\/centos1-drbd1-1.img’, fmt=qcow2 size=524288000 encryption=off cluster_size=0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
for centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
mint-1 images # qemu-img create -f qcow2 \/var\/disk1\/libvirt\/images\/centos6-drbd2-1.img 500M
Formatting ‘\/var\/disk1\/libvirt\/images\/centos1-drbd2-1.img’, fmt=qcow2 size=524288000 encryption=off cluster_size=0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
I have turned off apparomor on the KVM host.<\/div>\n

 <\/p>\n

add the centos6-drbd1-1.img to the DRBD machine centos6-drbd1 on the fly<\/div>\n

 <\/p>\n

on the KVM host<\/div>\n
\n\n\n<\/colgroup>\n\n\n
virsh # qemu-monitor-command centos6-32-drbd1 ‘pci_add auto storage file=\/var\/disk1\/libvirt\/images\/centos6-drbd1-1.img,if=scsi’
OK domain 0, bus 0, slot 7, function 0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on the KVM host<\/div>\n
\n\n\n<\/colgroup>\n\n\n
virsh # qemu-monitor-command centos6-32-drbd1 ‘info block’
drive-virtio-disk0: type=hd removable=0 file=\/var\/disk1\/libvirt\/images\/centos6-32-drbd1.img ro=0 drv=raw encrypted=0
scsi0-hd0: type=hd removable=0 file=\/var\/disk1\/libvirt\/images\/centos6-drbd1-1.img ro=0 drv=qcow2 encrypted=0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on the VM ( dmesg )<\/div>\n
\/dev\/sda has been added<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
sd 2:0:0:0: [sda] Attached SCSI disk<\/div>\n
sd 2:0:0:0: Attached scsi generic sg0 type 0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
do the same things on the VM centos6-drbd2<\/div>\n

 <\/p>\n

– add a storage device on both DRBD nodes.<\/div>\n

 <\/p>\n

on the KVM host , add the storage to centos6-32-drbd2 VM on the fly.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
virsh # qemu-monitor-command centos6-32-drbd2 ‘pci_add auto storage file=\/var\/di<\/div>\n
sk1\/libvirt\/images\/centos6-drbd2-1.img,if=scsi’<\/div>\n
OK domain 0, bus 0, slot 7, function 0<\/div>\n

<\/p>\n

virsh # qemu-monitor-command centos6-32-drbd2 ‘info block’<\/div>\n
drive-virtio-disk0: type=hd removable=0 file=\/var\/disk1\/libvirt\/images\/centos6-32-drbd2.img ro=0 drv=raw encrypted=0<\/div>\n
scsi0-hd0: type=hd removable=0 file=\/var\/disk1\/libvirt\/images\/centos6-drbd2-1.img ro=0 drv=qcow2 encrypted=0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make a partition for DRBD on both VMs with fdisk.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# LANG=C fdisk -l | grep sda<\/div>\n
Disk \/dev\/sda: 524 MB, 524288000 bytes<\/div>\n
\/dev\/sda1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01020 \u00a0\u00a0\u00a0\u00a0\u00a0511500+ \u00a083 \u00a0Linux<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Sample config has been installed under :<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# head -10 \/usr\/share\/doc\/drbd84-utils-8.4.1\/drbd.conf.example<\/div>\n
resource example {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0options {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0on-no-data-accessible suspend-io;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/div>\n

<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0net {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cram-hmac-alg “sha1”;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0shared-secret “secret_string”;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make a config file for DRBD , called disk0.res under \/etc\/drbd.d\/ directory.<\/div>\n

 <\/p>\n

drbd.conf file reads the following files<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# cat \/etc\/drbd.conf<\/div>\n
# You can find an example in \u00a0\/usr\/share\/doc\/drbd…\/drbd.conf.example<\/div>\n

<\/p>\n

include “drbd.d\/global_common.conf”;<\/div>\n
include “drbd.d\/*.res”;<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# uname -n<\/div>\n
centos6-drbd1.localdomain<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# ifconfig eth0 | grep “inet addr” | awk ‘{print $2}’<\/div>\n
addr:192.168.10.50<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# uname -n<\/div>\n
centos6-drbd2.localdomain<\/div>\n
[root@centos6-drbd2 ~]# ifconfig eth0 | grep “inet addr” | awk ‘{print $2}’<\/div>\n
addr:192.168.10.60<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\/etc\/drbd.d\/disk0.res file.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# cat \/etc\/drbd.d\/disk0.res<\/div>\n
resource disk0 {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0protocol C;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0net {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cram-hmac-alg sha1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0shared-secret “test”;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/div>\n

<\/p>\n

on centos6-drbd1.localdomain {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0device \/dev\/drbd0;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0disk \/dev\/sda1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.50:7788; # centos6-drbd1\u2019s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0meta-disk internal;<\/div>\n
}<\/div>\n

<\/p>\n

on centos6-drbd2.localdomain {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0device \/dev\/drbd0;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0disk \/dev\/sda1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.60:7788; # centos6-drbd2\u2019s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0meta-disk internal;<\/div>\n
}<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
copy same config to centos6-drbd2 node.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# scp \/etc\/drbd.d\/disk0.res root@192.168.10.60:\/etc\/drbd.d\/disk0.res<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– create meta data on both nodes<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm create-md disk0<\/div>\n

<\/p>\n

\u00a0–== \u00a0Thank you for participating in the global usage survey \u00a0==–<\/div>\n
The server’s response is:<\/div>\n

<\/p>\n

you are the 2135th user to install this version<\/div>\n
Writing meta data…<\/div>\n
initializing activity log<\/div>\n
NOT initializing bitmap<\/div>\n
New drbd meta data block successfully created.<\/div>\n
success<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# drbdadm create-md disk0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– start drbd daemon on both nodes<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd start<\/div>\n
Starting DRBD resources: [<\/div>\n
\u00a0\u00a0\u00a0\u00a0create res: disk0<\/div>\n
\u00a0\u00a0prepare disk: disk0<\/div>\n
\u00a0\u00a0\u00a0adjust disk: disk0<\/div>\n
\u00a0\u00a0\u00a0\u00a0adjust net: disk0<\/div>\n
]<\/div>\n
……….<\/div>\n
***************************************************************<\/div>\n
DRBD’s startup script waits for the peer node(s) to appear.<\/div>\n
– In case this node was already a degraded cluster before the<\/div>\n
\u00a0\u00a0reboot the timeout is 0 seconds. [degr-wfc-timeout]<\/div>\n
– If the peer was available before the reboot the timeout will<\/div>\n
\u00a0\u00a0expire after 0 seconds. [wfc-timeout]<\/div>\n
\u00a0\u00a0(These values are for resource ‘disk0’; 0 sec -> wait forever)<\/div>\n
To abort waiting enter ‘yes’ [ \u00a010]:<\/div>\n
.<\/div>\n
[root@centos6-drbd1 ~]# echo $?<\/div>\n
0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# \/etc\/init.d\/drbd start<\/div>\n
Starting DRBD resources: [<\/div>\n
\u00a0\u00a0\u00a0\u00a0create res: disk0<\/div>\n
\u00a0\u00a0prepare disk: disk0<\/div>\n
\u00a0\u00a0\u00a0adjust disk: disk0<\/div>\n
\u00a0\u00a0\u00a0\u00a0adjust net: disk0<\/div>\n
]<\/div>\n
.<\/div>\n
[root@centos6-drbd2 ~]# echo $?<\/div>\n
0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
check the status of DRBD<\/div>\n
\n\n\n<\/colgroup>\n\n\n
[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd status
drbd driver loaded OK; device status:
version: 8.4.1 (api:1\/proto:86-100)
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17
m:res \u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype
0:disk0 \u00a0Connected \u00a0Secondary\/Secondary \u00a0Inconsistent\/Inconsistent \u00a0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# \/etc\/init.d\/drbd status<\/div>\n
drbd driver loaded OK; device status:<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
m:res \u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype<\/div>\n
0:disk0 \u00a0Connected \u00a0Secondary\/Secondary \u00a0Inconsistent\/Inconsistent \u00a0C<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
status is secondary\/secondary , inconsistent.<\/div>\n

 <\/p>\n

To solve this , have the centos6-drbd1 node primary.<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm — –overwrite-data-of-peer primary all<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
check the status<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd status<\/div>\n
drbd driver loaded OK; device status:<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
m:res \u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype<\/div>\n
0:disk0 \u00a0SyncSource \u00a0Primary\/Secondary \u00a0UpToDate\/Inconsistent \u00a0C<\/div>\n
… \u00a0\u00a0\u00a0\u00a0\u00a0sync’ed: \u00a0\u00a0\u00a09.6% \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(465368\/511448)K<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
get things done<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd status<\/div>\n
drbd driver loaded OK; device status:<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
3GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
m:res \u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype<\/div>\n
0:disk0 \u00a0Connected \u00a0Primary\/Secondary \u00a0UpToDate\/UpToDate \u00a0C<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
centos6-drbd1 is primary and centos6-drbd2 is secondary.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm role all<\/div>\n
Primary\/Secondary<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# drbdadm role all<\/div>\n
Secondary\/Primary<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– create a filesystem<\/div>\n

 <\/p>\n

make a filesystem on primary node ( not secondary !! )<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm role all<\/div>\n
Primary\/Secondary<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# mkfs.ext4 \/dev\/drbd0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# cat \/proc\/drbd<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
0: cs:Connected ro:Primary\/Secondary ds:UpToDate\/UpToDate C r—–<\/div>\n
\u00a0\u00a0\u00a0ns:610747 nr:0 dw:99299 dr:517056 al:68 bm:32 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
0: cs:Connected ro:Secondary\/Primary ds:UpToDate\/UpToDate C r—–<\/div>\n
\u00a0\u00a0\u00a0ns:0 nr:74335 dw:74335 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– test<\/div>\n

 <\/p>\n

mount \/dev\/drbd0 to a directory.<\/div>\n

 <\/p>\n

on primary node<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# mount -t ext4 \/dev\/drbd0 data\/<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on primary ( centos6-drbd1 )<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# echo hello > data\/hello.txt<\/div>\n
[root@centos6-drbd1 ~]# cat data\/hello.txt<\/div>\n
hello<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
unmount the directory on the primary<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# umount \/root\/data\/<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
have the centos6-drbd1 secondary<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
Primary\/Secondary<\/div>\n
[root@centos6-drbd1 ~]# drbdadm secondary all<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# drbdadm role all<\/div>\n
Secondary\/Secondary<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
have the centos6-drbd2 primary<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# drbdadm role all<\/div>\n
Secondary\/Secondary<\/div>\n
[root@centos6-drbd2 ~]# drbdadm primary all<\/div>\n
[root@centos6-drbd2 ~]# drbdadm role all<\/div>\n
Primary\/Secondary<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
mount<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# mount -t ext4 \/dev\/drbd0 \/root\/data\/<\/div>\n
[root@centos6-drbd2 ~]# cat \/root\/data\/hello.txt<\/div>\n
hello<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
[ when using LVM ]<\/div>\n

 <\/p>\n

add two storage devices for LVM on both nodes.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
mint-1 images # qemu-img create -f qcow2 centos6-drbd1-lvm1.img 100M
Formatting ‘centos6-drbd1-lvm1.img’, fmt=qcow2 size=104857600 encryption=off cluster_size=0<\/p>\n

mint-1 images # qemu-img create -f qcow2 centos6-drbd1-lvm2.img 100M
Formatting ‘centos6-drbd1-lvm2.img’, fmt=qcow2 size=104857600 encryption=off cluster_size=0<\/p>\n

mint-1 images # qemu-img create -f qcow2 centos6-drbd2-lvm1.img 100M
Formatting ‘centos6-drbd2-lvm1.img’, fmt=qcow2 size=104857600 encryption=off cluster_size=0<\/p>\n

mint-1 images # qemu-img create -f qcow2 centos6-drbd2-lvm2.img 100M
Formatting ‘centos6-drbd2-lvm2.img’, fmt=qcow2 size=104857600 encryption=off cluster_size=0<\/p>\n

mint-1 images # ls *lvm*
centos6-drbd1-lvm1.img \u00a0centos6-drbd2-lvm1.img
centos6-drbd1-lvm2.img \u00a0centos6-drbd2-lvm2.img<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

add these devices to DRBD nodes.<\/div>\n

 <\/p>\n

on KVM host , add two storages to centos6-drbd1 node.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
virsh # qemu-monitor-command centos6-32-drbd1 ‘pci_add auto storage file=\/var\/disk1\/libvirt\/images\/centos6-drbd1-lvm1.img,if=scsi’
OK domain 0, bus 0, slot 8, function 0<\/p>\n

virsh # qemu-monitor-command centos6-32-drbd1 ‘pci_add auto storage file=\/var\/disk1\/libvirt\/images\/centos6-drbd1-lvm2.img,if=scsi’
OK domain 0, bus 0, slot 9, function 0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
virsh # qemu-monitor-command centos6-32-drbd2 ‘pci_add auto storage file=\/var\/di<\/div>\n
sk1\/libvirt\/images\/centos6-drbd2-lvm1.img,if=scsi’<\/div>\n
OK domain 0, bus 0, slot 8, function 0<\/div>\n
virsh # qemu-monitor-command centos6-32-drbd2 ‘pci_add auto storage file=\/var\/disk1\/libvirt\/images\/centos6-drbd2-lvm2.img,if=scsi’<\/div>\n
OK domain 0, bus 0, slot 9, function 0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\/dev\/sdb , \/dev\/sdc are for LVM<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# LANG=C fdisk -l | grep “\/dev\/sd*” | grep -v sda<\/div>\n
Disk \/dev\/sdb doesn’t contain a valid partition table<\/div>\n
Disk \/dev\/sdc doesn’t contain a valid partition table<\/div>\n
Disk \/dev\/sdb: 104 MB, 104857600 bytes<\/div>\n
Disk \/dev\/sdc: 104 MB, 104857600 bytes<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– create LVM partitions<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# fdisk \/dev\/sdb<\/div>\n
Command (m for help): n<\/div>\n
Command action<\/div>\n
\u00a0\u00a0e \u00a0\u00a0extended<\/div>\n
\u00a0\u00a0p \u00a0\u00a0primary partition (1-4)<\/div>\n
p<\/div>\n
Partition number (1-4): 1<\/div>\n
First cylinder (1-1024, default 1):<\/div>\n
Using default value 1<\/div>\n
Last cylinder, +cylinders or +size{K,M,G} (1-1024, default 1024):<\/div>\n
Using default value 1024<\/div>\n

<\/p>\n

Command (m for help): t<\/div>\n
Selected partition 1<\/div>\n
Hex code (type L to list codes): 8e<\/div>\n
Changed system type of partition 1 to 8e (Linux LVM)<\/div>\n

<\/p>\n

Command (m for help): p<\/div>\n

<\/p>\n

Disk \/dev\/sdb: 104 MB, 104857600 bytes<\/div>\n
4 heads, 50 sectors\/track, 1024 cylinders<\/div>\n
Units = cylinders of 200 * 512 = 102400 bytes<\/div>\n
Sector size (logical\/physical): 512 bytes \/ 512 bytes<\/div>\n
I\/O size (minimum\/optimal): 512 bytes \/ 512 bytes<\/div>\n
Disk identifier: 0x518bd64a<\/div>\n

<\/p>\n

\u00a0\u00a0Device Boot \u00a0\u00a0\u00a0\u00a0\u00a0Start \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0End \u00a0\u00a0\u00a0\u00a0\u00a0Blocks \u00a0\u00a0Id \u00a0System<\/div>\n
\/dev\/sdb1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01024 \u00a0\u00a0\u00a0\u00a0\u00a0102375 \u00a0\u00a08e \u00a0Linux LVM<\/div>\n

<\/p>\n

Command (m for help): w<\/div>\n
The partition table has been altered!<\/div>\n

<\/p>\n

Calling ioctl() to re-read partition table.<\/div>\n
Syncing disks.<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
do the same thing to \/dev\/sdc<\/div>\n
\n\n\n<\/colgroup>\n\n\n
[root@centos6-drbd1 ~]# LANG=C fdisk -l | grep “\/dev\/sd*” | grep -v sda
Disk \/dev\/sdb: 104 MB, 104857600 bytes
\/dev\/sdb1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01024 \u00a0\u00a0\u00a0\u00a0\u00a0102375 \u00a0\u00a08e \u00a0Linux LVM
Disk \/dev\/sdc: 104 MB, 104857600 bytes
\/dev\/sdc1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01024 \u00a0\u00a0\u00a0\u00a0\u00a0102375 \u00a0\u00a08e \u00a0Linux LVM<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make LVM partitions ( \/dev\/sdb , sdc ) on centos6-drbd2 as well.<\/div>\n

 <\/p>\n

centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# LANG=C fdisk -l | grep “\/dev\/sd*” | grep -v sda<\/div>\n
Disk \/dev\/sdb: 104 MB, 104857600 bytes<\/div>\n
\/dev\/sdb1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01024 \u00a0\u00a0\u00a0\u00a0\u00a0102375 \u00a0\u00a08e \u00a0Linux LVM<\/div>\n
Disk \/dev\/sdc: 104 MB, 104857600 bytes<\/div>\n
\/dev\/sdc1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01024 \u00a0\u00a0\u00a0\u00a0\u00a0102375 \u00a0\u00a08e \u00a0Linux LVM<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– create PV ( physical volume )<\/div>\n

 <\/p>\n

there\u2019s no pvcreate command.<\/div>\n
install lvm2 via yum<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# yum install -y lvm2<\/div>\n
[root@centos6-drbd2 ~]# yum install -y lvm2<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# pvcreate \/dev\/sdb1 \/dev\/sdc1<\/div>\n
\u00a0Writing physical volume data to disk “\/dev\/sdb1”<\/div>\n
\u00a0Physical volume “\/dev\/sdb1” successfully created<\/div>\n
\u00a0Writing physical volume data to disk “\/dev\/sdc1”<\/div>\n
\u00a0Physical volume “\/dev\/sdc1” successfully created<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# pvscan<\/div>\n
\u00a0PV \/dev\/sdb1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lvm2 [99.98 MiB]<\/div>\n
\u00a0PV \/dev\/sdc1 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lvm2 [99.98 MiB]<\/div>\n
\u00a0Total: 2 [199.95 MiB] \/ in use: 0 [0 \u00a0\u00a0] \/ in no VG: 2 [199.95 MiB]<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
do the same thing on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# pvcreate \/dev\/sdb1 \/dev\/sdc1<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– create VG ( volume group )<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# vgcreate -s 32m VolGroup01 \/dev\/sdb1 \/dev\/sdc1<\/div>\n
\u00a0Volume group “VolGroup01” successfully created<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# vgscan<\/div>\n
\u00a0Reading all physical volumes. \u00a0This may take a while…<\/div>\n
\u00a0Found volume group “VolGroup01” using metadata type lvm2<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# vgdisplay<\/div>\n
\u00a0— Volume group —<\/div>\n
\u00a0VG Name \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0VolGroup01<\/div>\n
\u00a0System ID<\/div>\n
\u00a0Format \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lvm2<\/div>\n
\u00a0Metadata Areas \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02<\/div>\n
\u00a0Metadata Sequence No \u00a01<\/div>\n
\u00a0VG Access \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0read\/write<\/div>\n
\u00a0VG Status \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0resizable<\/div>\n
\u00a0MAX LV \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00<\/div>\n
\u00a0Cur LV \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00<\/div>\n
\u00a0Open LV \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00<\/div>\n
\u00a0Max PV \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00<\/div>\n
\u00a0Cur PV \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02<\/div>\n
\u00a0Act PV \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02<\/div>\n
\u00a0VG Size \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0192.00 MiB<\/div>\n
\u00a0PE Size \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a032.00 MiB<\/div>\n
\u00a0Total PE \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a06<\/div>\n
\u00a0Alloc PE \/ Size \u00a0\u00a0\u00a0\u00a0\u00a0\u00a00 \/ 0<\/div>\n
\u00a0Free \u00a0PE \/ Size \u00a0\u00a0\u00a0\u00a0\u00a0\u00a06 \/ 192.00 MiB<\/div>\n
\u00a0VG UUID \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ZbTytp-s0st-HG2A-hB49-JuEX-f13I-829dgh<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# \u00a0vgcreate -s 32m VolGroup01 \/dev\/sdb1 \/dev\/sdc1<\/div>\n
\u00a0Volume group “VolGroup01” successfully created<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– create LV ( logical volume )<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# lvcreate -n LogVol01 -L 100M VolGroup01<\/div>\n
\u00a0Rounding up size to full physical extent 128.00 MiB<\/div>\n
\u00a0Logical volume “LogVol01” created<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# lvscan<\/div>\n
\u00a0ACTIVE \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0‘\/dev\/VolGroup01\/LogVol01’ [128.00 MiB] inherit<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# lvdisplay<\/div>\n
\u00a0— Logical volume —<\/div>\n
\u00a0LV Name \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/dev\/VolGroup01\/LogVol01<\/div>\n
\u00a0VG Name \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0VolGroup01<\/div>\n
\u00a0LV UUID \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00bCwiL-kMDE-sHyI-au1a-8Wwl-z67d-23KOkX<\/div>\n
\u00a0LV Write Access \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0read\/write<\/div>\n
\u00a0LV Status \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0available<\/div>\n
\u00a0# open \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00<\/div>\n
\u00a0LV Size \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0128.00 MiB<\/div>\n
\u00a0Current LE \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04<\/div>\n
\u00a0Segments \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02<\/div>\n
\u00a0Allocation \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0inherit<\/div>\n
\u00a0Read ahead sectors \u00a0\u00a0\u00a0\u00a0auto<\/div>\n
\u00a0– currently set to \u00a0\u00a0\u00a0\u00a0256<\/div>\n
\u00a0Block device \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0253:0<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
do the same thing on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# lvcreate -n LogVol01 -L 100M VolGroup01<\/div>\n
\u00a0Rounding up size to full physical extent 128.00 MiB<\/div>\n
\u00a0Logical volume “LogVol01” created<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– make ext4 filesystem on the LV<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# mkfs.ext4 \/dev\/VolGroup01\/LogVol01<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# mkfs.ext4 \/dev\/VolGroup01\/LogVol01<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

mount<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# mount -t ext4 \/dev\/VolGroup01\/LogVol01 \/root\/lvm_mnt\/<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# echo hello > \/root\/lvm_mnt\/hello.txt<\/div>\n
[root@centos6-drbd1 ~]# cat \/root\/lvm_mnt\/hello.txt<\/div>\n
hello<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# rm \/root\/lvm_mnt\/hello.txt<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
If you want to manage LVM via GUI , you can use \u201csystem-config-lvm\u201d which you can install via yum.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# yum install system-config-lvm<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
start GUI tool<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
# system-config-lvm<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

<\/p>\n

– set up DRBD configuration<\/div>\n

 <\/p>\n

at first stop DRBD , unmount LV.<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# umount \/root\/lvm_mnt\/<\/div>\n
[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd stop<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# \/etc\/init.d\/drbd stop<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make a DRBD cofnig file for this LVM.<\/div>\n

 <\/p>\n

on centos6-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# vi \/etc\/drbd.d\/lvm_disk1.res<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# cat \/etc\/drbd.d\/lvm_disk1.res<\/div>\n
resource lvm_disk1 {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0protocol C;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0net {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cram-hmac-alg sha1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0shared-secret “test”;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/div>\n

<\/p>\n

on centos6-drbd1.localdomain {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0device \/dev\/drbd1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0disk \/dev\/VolGroup01\/LogVol01;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.50:7788; # centos6-drbd1’s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0meta-disk internal;<\/div>\n
}<\/div>\n

<\/p>\n

on centos6-drbd2.localdomain {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0device \/dev\/drbd1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0disk \/dev\/VolGroup01\/LogVol01;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.60:7788; # centos6-drbd2’s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0meta-disk internal;<\/div>\n
}<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
copy it to centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# scp \/etc\/drbd.d\/lvm_disk1.res root@192.168.10.60:\/etc\/dr<\/div>\n
bd.d\/lvm_disk1.res<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
nnn , error<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm create-md lvm_disk1<\/div>\n
drbd.d\/lvm_disk1.res:11: conflicting use of IP ‘192.168.10.50:7788’ …<\/div>\n
drbd.d\/disk0.res:11: IP ‘192.168.10.50:7788’ first used here.<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
I need to change the port # per DRBD resource.<\/div>\n

 <\/p>\n

Okay , I\u2019ll use 7789 for this LVM\u2019s DRBD<\/div>\n

 <\/p>\n

confirm 7789 is not used<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# lsof -ni:7789<\/div>\n
[root@centos6-drbd1 ~]#<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# cat \/etc\/drbd.d\/lvm_disk1.res<\/div>\n
resource lvm_disk1 {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0protocol C;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0net {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cram-hmac-alg sha1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0shared-secret “test”;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/div>\n

<\/p>\n

on centos6-drbd1.localdomain {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0device \/dev\/drbd1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0disk \/dev\/VolGroup01\/LogVol01;<\/div>\n
# \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.50:7788; # centos6-drbd1’s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.50:7789; # centos6-drbd1’s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0meta-disk internal;<\/div>\n
}<\/div>\n

<\/p>\n

on centos6-drbd2.localdomain {<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0device \/dev\/drbd1;<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0disk \/dev\/VolGroup01\/LogVol01;<\/div>\n
# \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.60:7788; # centos6-drbd2’s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0address 192.168.10.60:7789; # centos6-drbd2’s IP<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0meta-disk internal;<\/div>\n
}<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
copy it to centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# !877<\/div>\n
scp \/etc\/drbd.d\/lvm_disk1.res root@192.168.10.60:\/etc\/drbd.d\/lvm_disk1.res<\/div>\n
root@192.168.10.60’s password:<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
try again.<\/div>\n

 <\/p>\n

nnn , erro ,, erro code is 40.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm create-md lvm_disk1<\/div>\n
md_offset 134213632<\/div>\n
al_offset 134180864<\/div>\n
bm_offset 134176768<\/div>\n

<\/p>\n

Found ext3 filesystem<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0131072 kB data area apparently used<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0131032 kB left usable by current configuration<\/div>\n

<\/p>\n

Device size would be truncated, which<\/div>\n
would corrupt data and result in<\/div>\n
‘access beyond end of device’ errors.<\/div>\n
You need to either<\/div>\n
\u00a0\u00a0* use external meta data (recommended)<\/div>\n
\u00a0\u00a0* shrink that filesystem first<\/div>\n
\u00a0\u00a0* zero out the device (destroy the filesystem)<\/div>\n
Operation refused.<\/div>\n

<\/p>\n

Command ‘drbdmeta 1 v08 \/dev\/VolGroup01\/LogVol01 internal create-md’ terminated with exit code 40<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
zero out the LV.<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# dd if=\/dev\/zero of=\/dev\/VolGroup01\/LogVol01 bs=1M count=1<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# dd if=\/dev\/zero of=\/dev\/VolGroup01\/LogVol01 bs=1M count=1<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
try again<\/div>\n

 <\/p>\n

on centos-drbd1<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm create-md lvm_disk1<\/div>\n
Writing meta data…<\/div>\n
initializing activity log<\/div>\n
NOT initializing bitmap<\/div>\n
New drbd meta data block successfully created.<\/div>\n
success<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
do the same thing on centos-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# drbdadm create-md lvm_disk1<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– start DRBD on both nodes<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd start<\/div>\n
Starting DRBD resources: [<\/div>\n
\u00a0\u00a0\u00a0\u00a0create res: disk0 lvm_disk1<\/div>\n
\u00a0\u00a0prepare disk: disk0 lvm_disk1<\/div>\n
\u00a0\u00a0\u00a0adjust disk: disk0 lvm_disk1<\/div>\n
\u00a0\u00a0\u00a0\u00a0adjust net: disk0 lvm_disk1<\/div>\n
]<\/div>\n
………<\/div>\n
[root@centos6-drbd1 ~]#<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd status<\/div>\n
drbd driver loaded OK; device status:<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
m:res \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype<\/div>\n
0:disk0 \u00a0\u00a0\u00a0\u00a0\u00a0Connected \u00a0Secondary\/Secondary \u00a0UpToDate\/UpToDate \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0C<\/div>\n
1:lvm_disk1 \u00a0Connected \u00a0Secondary\/Secondary \u00a0Inconsistent\/Inconsistent \u00a0C<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# cat \/proc\/drbd<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
0: cs:Connected ro:Secondary\/Secondary ds:UpToDate\/UpToDate C r—–<\/div>\n
\u00a0\u00a0\u00a0ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:0<\/div>\n
1: cs:Connected ro:Secondary\/Secondary ds:Inconsistent\/Inconsistent C r—–<\/div>\n
\u00a0\u00a0\u00a0ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:131032<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
on centos6-drbd1 ( initialize DRBD disk )<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm — –overwrite-data-of-peer primary all<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# \/etc\/init.d\/drbd status<\/div>\n
drbd driver loaded OK; device status:<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
m:res \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype<\/div>\n
0:disk0 \u00a0\u00a0\u00a0\u00a0\u00a0Connected \u00a0Primary\/Secondary \u00a0UpToDate\/UpToDate \u00a0C<\/div>\n
1:lvm_disk1 \u00a0Connected \u00a0Primary\/Secondary \u00a0UpToDate\/UpToDate \u00a0C<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# drbdadm role all<\/div>\n
Primary\/Secondary<\/div>\n
Primary\/Secondary<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# drbd-overview<\/div>\n
\u00a00:disk0\/0 \u00a0\u00a0\u00a0\u00a0\u00a0Connected Primary\/Secondary UpToDate\/UpToDate C r—–<\/div>\n
\u00a01:lvm_disk1\/0 \u00a0Connected Primary\/Secondary UpToDate\/UpToDate C r—– \/root\/lvm_mnt ext4 124M 5.6M 113M 5%<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# drbdadm role all<\/div>\n
Secondary\/Primary<\/div>\n
Secondary\/Primary<\/div>\n

<\/p>\n

[root@centos6-drbd2 ~]# \/etc\/init.d\/drbd status<\/div>\n
drbd driver loaded OK; device status:<\/div>\n
version: 8.4.1 (api:1\/proto:86-100)<\/div>\n
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag@Build32R6, 2011-12-21 06:07:17<\/div>\n
m:res \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0cs \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ro \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ds \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0p \u00a0mounted \u00a0fstype<\/div>\n
0:disk0 \u00a0\u00a0\u00a0\u00a0\u00a0Connected \u00a0Secondary\/Primary \u00a0UpToDate\/UpToDate \u00a0C<\/div>\n
1:lvm_disk1 \u00a0Connected \u00a0Secondary\/Primary \u00a0UpToDate\/UpToDate \u00a0C<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
– make filesystem on the primary node<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# mkfs.ext4 \/dev\/drbd1<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
mount<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# mount -t ext4 \/dev\/drbd1 \/root\/lvm_mnt\/<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make a file<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# echo “hi” > \/root\/lvm_mnt\/hi.txt<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# cat \/root\/lvm_mnt\/hi.txt<\/div>\n
hi<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
unmount<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# umount \/root\/lvm_mnt\/<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make centos6-drbd1 secondary<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm secondary all<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbdadm role all<\/div>\n
Secondary\/Secondary<\/div>\n
Secondary\/Secondary<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
make centos6-drbd2 priamry<\/div>\n

 <\/p>\n

on centos6-drbd2<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# drbdadm role all<\/div>\n
Secondary\/Secondary<\/div>\n
Secondary\/Secondary<\/div>\n
[root@centos6-drbd2 ~]# drbdadm primary all<\/div>\n
[root@centos6-drbd2 ~]#<\/div>\n

<\/p>\n

[root@centos6-drbd2 ~]# drbd-overview<\/div>\n
\u00a00:disk0\/0 \u00a0\u00a0\u00a0\u00a0\u00a0Connected Primary\/Secondary UpToDate\/UpToDate C r—–<\/div>\n
\u00a01:lvm_disk1\/0 \u00a0Connected Primary\/Secondary UpToDate\/UpToDate C r—–<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd2 ~]# mkdir \/root\/lvm_mnt<\/div>\n

<\/p>\n

[root@centos6-drbd2 ~]# mount -t ext4 \/dev\/drbd1 \/root\/lvm_mnt\/<\/div>\n

<\/p>\n

[root@centos6-drbd2 ~]# ls \/root\/lvm_mnt\/<\/div>\n
hi.txt \u00a0lost+found<\/div>\n
[root@centos6-drbd2 ~]# cat \/root\/lvm_mnt\/hi.txt<\/div>\n
hi<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
disable resources<\/div>\n
\n\n\n<\/colgroup>\n\n\n
\n
[root@centos6-drbd1 ~]# drbd-overview<\/div>\n
\u00a00:disk0\/0 \u00a0\u00a0\u00a0\u00a0\u00a0Connected Secondary\/Primary UpToDate\/UpToDate C r—–<\/div>\n
\u00a01:lvm_disk1\/0 \u00a0Connected Secondary\/Primary UpToDate\/UpToDate C r—–<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# drbdadm down disk0<\/div>\n
[root@centos6-drbd1 ~]# drbdadm down lvm_disk1<\/div>\n

<\/p>\n

[root@centos6-drbd1 ~]# drbd-overview<\/div>\n
\u00a00:disk0\/0 \u00a0\u00a0\u00a0\u00a0\u00a0Unconfigured . . . .<\/div>\n
\u00a01:lvm_disk1\/0 \u00a0Unconfigured . . . .<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

 <\/p>\n

Here is an explanation of how to set up DRBD on CentOS6. # cat \/etc\/redhat-release CentOS release 6.2 (Final) <\/p>\n

# uname -ri 2.6.32-220.7.1.el6.i686 i386 <\/p>\n

 <\/p>\n

# rpm -qa | grep drbd kmod-drbd84-8.4.1-1.el6.elrepo.i686 drbd84-utils-8.4.1-1.el6.elrepo.i686 Hostname ( uname \u2013n ) of DBRD nodes are: centos6-drbd1.localdomain centos6-drbd2.localdomain <\/p>\n

 <\/p>\n

These nodes are running as VMs on a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"_links":{"self":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/1096"}],"collection":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1096"}],"version-history":[{"count":2,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/1096\/revisions"}],"predecessor-version":[{"id":1098,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/1096\/revisions\/1098"}],"wp:attachment":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1096"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1096"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1096"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}