1. DRBD is The Distributed Replicated Block Device.

1. Two computers that are connected to a common switch or hub.
2. The two computers should also be connected by a Null Modem serial cable
   to provide the 'heartbeat' system an alternate means of communication.
3. Each system must independantly have sufficient disk space to provide file service.

host-a  10.0.0.10
host-b  10.0.0.20
fs-cluster 10.0.0.30

1. 양쪽 장비(both hosts) 모두 컴파일하고, 설치한다.

   # apt-get install drbd0.7-module-source
   # apt-get install drbd0.7-utils
   # apt-get install dpatch
   # cd /usr/src
   # tar -zxf drbd0.7.tar.gz
   # cd /usr/src/modules/drbd
   # module-assistant prepare
   # module-assistant automatic-install drbd0.7-module-source
      Navigate the module package creation procedure as logically as
      possible; details for this procedure are not provided.
   # cd /usr/src
   # dpkg -i drbd0.7-module-2.4.27-2-k7_0.7.10-3+2.4.27-8_i386.deb

1. 양쪽 장비에 /etc/drbd.conf 파일에 동일하게 구성한다.

   resource drbd-resource-0 {
     protocol C;
     incon-degr-cmd "halt -f"; # killall heartbeat would be a good alternative :->
     disk {
       on-io-error panic;
     }
     syncer {
       rate 10M; # Note: 'M' is MegaBytes, not MegaBits
     }
     on host-a {
       device    /dev/drbd0;
       disk      /dev/hda8;
       address   10.0.0.10:7789;
       meta-disk  internal;
     }
     on host-b {
       device    /dev/drbd0;
       disk      /dev/hda8;
       address   10.0.0.20:7789;
       meta-disk  internal;
     }
   }

2. 양쪽장비에서 DRBD를 실행한다.

   # /etc/init.d/drbd start

3. 장비 중 하나를 Primary 로 선언한다.

   host-a: # drbdadm primary all

4. DRBD 지정한다.

   host-a: # drbdsetup /dev/drbd0 primary --do-what-I-say

5. Primary 장비에서 DRBD를 위한 파일시스템을 활성화시킨다.

   host-a: # mkreiserfs /dev/drbd0  (or mke2fs, or whatever filesystem you
   prefer)
   host-a: # mkdir /share
   host-a: # mkdir /share/spool0
   host-a: # mount /dev/drbd0 /share/spool0

6. Primary 장비에서 NFS 아래의 공유디렉토리를 생성한다.

   host-a: # mkdir /share/spool0/data

7. 양쪽노드에 NFS 설정을 한다.
   1. Debian 패키지를 설치한다.

      # apt-get install nfs-kernel-server

   2. NFS 서버를 정지시킨다.

      # /etc/init.d/nfs-kernel-server stop

   3. /etc/exports 파일을 설정한다.

      # echo "/share/spool0/data 10.3.11.0/255.255.255.0(rw,sync)" >> /etc/exports

   4. 양쪽장비의 NFS 서비스를 자동으로 실행되지 않게 한다.

      # update-rc.d -f nfs-kernel-server remove
      (for non-Debian systems you can probably just delete /etc/init.d/
      nfs or /etc/init.d/nfs-server)

   5. Primary 장비에서 nfs 설정을 공유디스크에 카피하고, 링크시킨다.

      host-a: # mv /var/lib/nfs /share/spool0/varlibnfs
      host-a: # ln -s /share/spool0/varlibnfs /var/lib/nfs

   6. /etc/default/nfs-common 파일설정을 한다.

      # vi /etc/default/nfs-common
      ...
      'STATDOPTS="-n my_clusters_name"
      ...

1. 패키지를 설치한다.

   # apt-get install heartbeat

2. 양쪽 장비의 /etc/ha.d/ha.cf 를 설정한다.
   아래는 Primary 장비의 설정이다.
   장비별로 ucast는 다르다.
   node-b는 10.0.0.20 대신 ucast eth0 10.0.0.10 설정한다.

   keepalive 1
   deadtime 10
   warntime 5
   initdead 60
   udpport 694
   baud 19200
   serial /dev/ttyS0
   ucast eth0 10.0.0.20
   auto_failback off
   watchdog /dev/watchdog
   node node-a
   node node-b

   • auto_failback is off; we should not fail back unless a human has confirmed that the DRBD state is consistent
3. heartbeat resource 생성한다.

   # echo 'killall -9 nfsd ; exit 0' > /etc/heartbeat/resource.d/killnfsd
   # chmod 755 /etc/heartbeat/resource.d/killnfsd

4. /etc/heartbeat/haresources 에 Primary 장비에 설정한다.

   host-a  drbddisk::drbd-resource-0 \
           Filesystem::/dev/drbd0::/share/spool0/data::reiserfs \
           killnfsd \
           nfs-common \
           nfs-kernel-server \
           Delay::3::0 \
           IPaddr::10.0.0.30/24/eth0

5. HA 서버로부터 마운트시킨다.

   client-a: # mkdir /mnt/hafs
   client-a: # echo "fs-cluster:/share/spool0/data /mnt/hafs nfs defaults 0 0" >> /etc/fstab
   client-a: # mount -a

1. http://www.linux-ha.org/DRBD/NFS