High-Availability Storage With GlusterFS On Fedora 12 - Automatic File Replication (Mirror) Across Two Storage Servers

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Author: Falko Timme <ft [at] falkotimme [dot] com>
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Last edited 02/22/2010

This tutorial shows how to set up a high-availability storage with two storage servers (Fedora 12) that use GlusterFS. Each storage server will be a mirror of the other storage server, and files will be replicated automatically across both storage servers. The client system (Fedora 12 as well) will be able to access the storage as if it was a local filesystem. GlusterFS is a clustered file-system capable of scaling to several peta-bytes. It aggregates various storage bricks over Infiniband RDMA or TCP/IP interconnect into one large parallel network file system. Storage bricks can be made of any commodity hardware such as x86_64 servers with SATA-II RAID and Infiniband HBA.

I do not issue any guarantee that this will work for you!

1 Preliminary Note

In this tutorial I use three systems, two servers and a client:

• server1.example.com: IP address 192.168.0.100 (server)
• server2.example.com: IP address 192.168.0.101 (server)
• client1.example.com: IP address 192.168.0.102 (client)

All three systems should be able to resolve the other systems' hostnames. If this cannot be done through DNS, you should edit the /etc/hosts file so that it contains the following lines on all three systems:

vi /etc/hosts

[...]
192.168.0.100           server1.example.com server1
192.168.0.101           server2.example.com server2
192.168.0.102           client1.example.com client1
[...]

(It is also possible to use IP addresses instead of hostnames in the following setup. If you prefer to use IP addresses, you don't have to care about whether the hostnames can be resolved or not.)

2 Setting Up The GlusterFS Servers

server1.example.com/server2.example.com:

The GlusterFS server is available as a package for Fedora 12, therefore we can install it as follows:

yum install glusterfs-server

The command

glusterfs --version

should now show the GlusterFS version that you've just installed (2.0.9 in this case):

[root@server1 ~]# glusterfs --version
glusterfs 2.0.9 built on Jan  3 2010 00:12:49
Repository revision: v2.0.9
Copyright (c) 2006-2009 Gluster Inc. <http://www.gluster.com>
GlusterFS comes with ABSOLUTELY NO WARRANTY.
You may redistribute copies of GlusterFS under the terms of the GNU General Public License.
[root@server1 ~]#

Next we create a few directories:

mkdir /data/
mkdir /data/export
mkdir /data/export-ns

Now we create the GlusterFS server configuration file /etc/glusterfs/glusterfsd.vol (we make a backup of the original /etc/glusterfs/glusterfsd.vol file first) which defines which directory will be exported (/data/export) and what client is allowed to connect (192.168.0.102 = client1.example.com):

cp /etc/glusterfs/glusterfsd.vol /etc/glusterfs/glusterfsd.vol_orig
cat /dev/null > /etc/glusterfs/glusterfsd.vol
vi /etc/glusterfs/glusterfsd.vol

volume posix
  type storage/posix
  option directory /data/export
end-volume

volume locks
  type features/locks
  subvolumes posix
end-volume

volume brick
  type performance/io-threads
  option thread-count 8
  subvolumes locks
end-volume

volume server
  type protocol/server
  option transport-type tcp
  option auth.addr.brick.allow 192.168.0.102
  subvolumes brick
end-volume

Please note that it is possible to use wildcards for the IP addresses (like 192.168.*) and that you can specify multiple IP addresses separated by comma (e.g. 192.168.0.102,192.168.0.103).

Afterwards we create the system startup links for the GlusterFS server and start it:

chkconfig --levels 35 glusterfsd on
/etc/init.d/glusterfsd start