Creating An NFS-Like Standalone Storage Server With GlusterFS On CentOS 5.4

This tutorial shows how to set up a standalone storage server on CentOS 5.4. Instead of NFS, I will use GlusterFS here.

The client system 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 two systems, a server and a client:

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

Both systems should be able to resolve the other system's hostname. If this cannot be done through DNS, you should edit the /etc/hosts file so that it contains the following two lines on both systems:

vi /etc/hosts

[...] 192.168.0.100 server1.example.com server1 192.168.0.101 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 Server

server1.example.com:

GlusterFS isn't available as a package for CentOS 5.4, therefore we have to build it ourselves. First we install the prerequisites:

# yum groupinstall 'Development Tools'

# yum groupinstall 'Development Libraries'

# yum install libibverbs-devel fuse-devel

Then we download the latest GlusterFS release from http://www.gluster.org/download.php and build it as follows:

# cd /tmp
# wget http://ftp.gluster.com/pub/gluster/glusterfs/2.0/LATEST/glusterfs-2.0.9.tar.gz
# tar xvfz glusterfs-2.0.9.tar.gz
# cd glusterfs-2.0.9
# ./configure

At the end of the ./configure command, you should see something like this:

[...]

GlusterFS configure summary
===========================
FUSE client        : yes
Infiniband verbs   : yes
epoll IO multiplex : yes
Berkeley-DB        : yes
libglusterfsclient : yes
argp-standalone    : no

[root@server1 glusterfs-2.0.9]#

make && make install
ldconfig

Check the GlusterFS version afterwards (should be 2.0.9):

glusterfs --version

[root@server1 glusterfs-2.0.9]# glusterfs --version
glusterfs 2.0.9 built on Mar 1 2010 15:34:50
Repository revision: v2.0.9
Copyright (c) 2006-2009 Gluster Inc.
GlusterFS comes with ABSOLUTELY NO WARRANTY.

You may redistribute copies of GlusterFS under the terms of the GNU General Public License.
[root@server1 glusterfs-2.0.9]#

Next we create a few directories:

# mkdir /data/
# mkdir /data/export
# mkdir /data/export-ns
# mkdir /etc/glusterfs

Now we create the GlusterFS server configuration file /etc/glusterfs/glusterfsd.vol which defines which directory will be exported (/data/export) and what client is allowed to connect (192.168.0.101 = client1.example.com):

# vi /etc/glusterfs/glusterfsd.vol

volume posix type storage/posix option directory /data/export end-volume volume locks type features/locks option mandatory-locks on 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 192.168.0.101 # Edit and add list of allowed clients comma separated IP addrs(names) here 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. 192.168.0.101,192.168.0.102).

Afterwards we create the following symlink...

# ln -s /usr/local/sbin/glusterfsd /sbin/glusterfsd

... and then the system startup links for the GlusterFS server and start it:

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

3 Setting Up The GlusterFS Client

client1.example.com:

GlusterFS isn't available as a package for CentOS 5.4, therefore we have to build it ourselves. First we install the prerequisites:

# yum groupinstall 'Development Tools'

# yum groupinstall 'Development Libraries'

# yum install libibverbs-devel fuse-devel

Then we load the fuse kernel module...

# modprobe fuse

... and create the file /etc/rc.modules with the following contents so that the fuse kernel module will be loaded automatically whenever the system boots:

vi /etc/rc.modules

modprobe fuse

Make the file executable:

# chmod +x /etc/rc.modules

Then we download the GlusterFS 2.0.9 sources (please note that this is the same version that is installed on the server!) and build GlusterFS as follows:

# cd /tmp

# wget http://ftp.gluster.com/pub/gluster/glusterfs/2.0/LATEST/glusterfs-2.0.9.tar.gz
# tar xvfz glusterfs-2.0.9.tar.gz
# cd glusterfs-2.0.9
# ./configure

At the end of the ./configure command, you should see something like this:

[...]
GlusterFS configure summary
===========================
FUSE client        : yes
Infiniband verbs   : yes
epoll IO multiplex : yes
Berkeley-DB        : yes
libglusterfsclient : yes
argp-standalone    : no

make && make install
ldconfig

Check the GlusterFS version afterwards (should be 2.0.9):

glusterfs --version

[root@client1 glusterfs-2.0.9]# glusterfs --version
glusterfs 2.0.9 built on Mar 1 2010 15:58:06
Repository revision: v2.0.9
Copyright (c) 2006-2009 Gluster Inc.
GlusterFS comes with ABSOLUTELY NO WARRANTY.

You may redistribute copies of GlusterFS under the terms of the GNU General Public License.
[root@client1 glusterfs-2.0.9]#

Then we create the following two directories:

# mkdir /mnt/glusterfs
# mkdir /etc/glusterfs

Next we create the file /etc/glusterfs/glusterfs.vol:

# vi /etc/glusterfs/glusterfs.vol

volume remote type protocol/client option transport-type tcp option remote-host server1.example.com # can be IP or hostname option remote-subvolume brick end-volume volume writebehind type performance/write-behind option window-size 4MB subvolumes remote end-volume volume cache type performance/io-cache option cache-size 512MB subvolumes writebehind end-volume

Make sure you use the correct server hostname or IP address in the option remote-host line!

That's it! Now we can mount the GlusterFS filesystem to /mnt/glusterfs with one of the following two commands:

# glusterfs -f /etc/glusterfs/glusterfs.vol /mnt/glusterfs

or

# mount -t glusterfs /etc/glusterfs/glusterfs.vol /mnt/glusterfs

You should now see the new share in the outputs of...

mount

[root@client1 ~]# mount

/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
glusterfs#/etc/glusterfs/glusterfs.vol on /mnt/glusterfs type fuse (rw,allow_other,default_permissions,max_read=131072)
[root@client1 ~]#

... and...

df -h

[root@client1 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                       29G  2.2G   25G   9% /
/dev/sda1              99M   13M   82M  14% /boot
tmpfs                 187M     0  187M   0% /dev/shm
glusterfs#/etc/glusterfs/glusterfs.vol
                       28G  2.3G   25G   9% /mnt/glusterfs
[root@client1 ~]#

Instead of mounting the GlusterFS share manually on the client, you could modify /etc/fstab so that the share gets mounted automatically when the client boots.

Open /etc/fstab and append the following line:

# vi /etc/fstab

[...] /etc/glusterfs/glusterfs.vol /mnt/glusterfs glusterfs defaults 0 0

To test if your modified /etc/fstab is working, reboot the client:

# reboot

After the reboot, you should find the share in the outputs of...

df -h

... and...

mount

4 Links

• GlusterFS: http://www.gluster.org/
• CentOS: http://www.centos.org/