4 Install NFS Server

Next we install the NFS server on both server1 and server2:

server1/server2:

apt-get install nfs-kernel-server

Then we remove the system bootup links for NFS because NFS will be started and controlled by heartbeat in our setup:

server1/server2:

update-rc.d -f nfs-kernel-server remove
update-rc.d -f nfs-common remove

We want to export the directory /data/export (i.e., this will be our NFS share that our web server cluster nodes will use to serve web content), so we edit /etc/exports on server1 and server2. It should contain only the following line:

server1/server2:

/etc/exports:

/data/export/ 192.168.0.0/255.255.255.0(rw,no_root_squash,no_all_squash,sync)

This means that /data/export will be accessible by all systems from the 192.168.0.x subnet. You can limit access to a single system by using 192.168.0.100/255.255.255.255 instead of 192.168.0.0/255.255.255.0, for example. See

man 5 exports

to learn more about this.

Later in this tutorial we will create /data/exports on our empty (and still unmounted!) partition /dev/sda8.

5 Install DRBD

Next we install DRBD on both server1 and server2:

server1/server2:

apt-get install kernel-headers-2.6.8-2-386 drbd0.7-module-source drbd0.7-utils
cd /usr/src/
tar xvfz drbd0.7.tar.gz
cd modules/drbd/drbd
make
make install

Then edit /etc/drbd.conf on server1 and server2. It must be identical on both systems and looks like this:

server1/server2:

/etc/drbd.conf:

resource r0 {

 protocol C;
 incon-degr-cmd "halt -f";

 startup {
    degr-wfc-timeout 120;    # 2 minutes.
  }

  disk {
    on-io-error   detach;
  }

  net {

  }

  syncer {

    rate 10M;

    group 1;

    al-extents 257;
  }

 on server1 {                # ** EDIT ** the hostname of server 1 (uname -n)
   device     /dev/drbd0;        #
   disk       /dev/sda8;         # ** EDIT ** data partition on server 1
   address    192.168.0.172:7788; # ** EDIT ** IP address on server 1
   meta-disk  /dev/sda7[0];      # ** EDIT ** 128MB partition for DRBD on server 1
  }

 on server2 {                # ** EDIT ** the hostname of server 2 (uname -n)
   device    /dev/drbd0;         #
   disk      /dev/sda8;          # ** EDIT ** data partition on server 2
   address   192.168.0.173:7788;  # ** EDIT ** IP address on server 2
   meta-disk /dev/sda7[0];       # ** EDIT ** 128MB partition for DRBD on server 2
  }

}

As resource name you can use whatever you like. Here it's r0. Please make sure you put the correct hostnames of server1 and server2 into /etc/drbd.conf. DRBD expects the hostnames as they are shown by the command

uname -n

If you have set server1 and server2 respectively as hostnames during the basic Debian installation, then the output of uname -n should be server1 and server2.

Also make sure you replace the IP addresses and the disks appropriately. If you use /dev/hda instead of /dev/sda, please put /dev/hda8 instead of /dev/sda8 into /etc/drbd.conf (the same goes for the meta-disk where DRBD stores its meta data). /dev/sda8 (or /dev/hda8...) will be used as our NFS share later on.