Setting Up A Highly Available NFS Server - Page 2

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.

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From: Anonymous at: 2006-07-13 21:56:56

this may be pretty obvious, but when you install the kernel-headers  package, make sure you're using the version which match your running kernel (for example kernel-headers-2.6.8-2-686-smp ).

 

From: at: 2007-01-11 05:23:25

Yes, this is VERY IMPORTANT.

 When installing your kernel headers, simply do this:

apt-get install kernel-headers-`uname -r` drbd0.7-module-source drbd0.7-utils

 

The `uname -r` will automatically insert your proper kernel version into the command.

Try running the command uname -r once, by itself, to see.

From: Jason Priebe at: 2009-04-08 01:17:40

We considered the DRBD approach as well when we looked to replace our NetApp cluster with a linux-based solution.  We settled on a slightly different approach (using RHEL and Cluster Suite). I welcome you to read my blog post about it.