There is a new version of this tutorial available for Ubuntu 12.10 (Quantal Quetzal).

Distributed Storage Across Four Storage Nodes With GlusterFS On Ubuntu 9.10 - Page 2

3 Setting Up The GlusterFS Client

client1.example.com:

On the client, we can install the GlusterFS client as follows:

aptitude install glusterfs-client glusterfs-server

Then we create the following directory:

mkdir /mnt/glusterfs

Next we create the file /etc/glusterfs/glusterfs.vol (we make a backup of the original /etc/glusterfs/glusterfs.vol file first):

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

volume remote1
  type protocol/client
  option transport-type tcp
  option remote-host server1.example.com
  option remote-subvolume brick
end-volume

volume remote2
  type protocol/client
  option transport-type tcp
  option remote-host server2.example.com
  option remote-subvolume brick
end-volume

volume remote3
  type protocol/client
  option transport-type tcp
  option remote-host server3.example.com
  option remote-subvolume brick
end-volume

volume remote4
  type protocol/client
  option transport-type tcp
  option remote-host server4.example.com
  option remote-subvolume brick
end-volume

volume distribute
  type cluster/distribute
  subvolumes remote1 remote2 remote3 remote4
end-volume

volume writebehind
  type performance/write-behind
  option window-size 1MB
  subvolumes distribute
end-volume

volume cache
  type performance/io-cache
  option cache-size 512MB
  subvolumes writebehind
end-volume

Make sure you use the correct server hostnames or IP addresses in the option remote-host lines!

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

[email protected]:~# mount
/dev/mapper/client1-root on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw)
none on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type tmpfs (rw,mode=0755)
none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
none on /dev/shm type tmpfs (rw,nosuid,nodev)
none on /var/run type tmpfs (rw,nosuid,mode=0755)
none on /var/lock type tmpfs (rw,noexec,nosuid,nodev)
none on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
/dev/sda5 on /boot type ext2 (rw)
/etc/glusterfs/glusterfs.vol on /mnt/glusterfs type fuse.glusterfs (rw,max_read=131072,allow_other,default_permissions)
[email protected]:~#

... and...

df -h

[email protected]:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/client1-root
                       29G  808M   27G   3% /
udev                  122M  152K  121M   1% /dev
none                  122M     0  122M   0% /dev/shm
none                  122M   36K  122M   1% /var/run
none                  122M     0  122M   0% /var/lock
none                  122M     0  122M   0% /lib/init/rw
/dev/sda5             228M   15M  202M   7% /boot
/etc/glusterfs/glusterfs.vol
                      103G  3.2G   95G   4% /mnt/glusterfs
[email protected]:~#

(server1.example.com, server2.example.com, server3.example.com, and server4.example.com each have about 26GB of space for the GlusterFS filesystem, so that the resulting share has a size of about 4 x 26GB (103GB).)

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 Testing

Now let's create some test files on the GlusterFS share:

client1.example.com:

touch /mnt/glusterfs/test1
touch /mnt/glusterfs/test2
touch /mnt/glusterfs/test3
touch /mnt/glusterfs/test4
touch /mnt/glusterfs/test5
touch /mnt/glusterfs/test6

Now let's check the /data/export directory on server1.example.com, server2.example.com, server3.example.com, and server4.example.com. You will notice that each storage node holds only a part of the files/directories that make up the GlusterFS share on the client:

server1.example.com:

ls -l /data/export

[email protected]:~# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2009-12-21 14:58 test1
-rw-r--r-- 1 root root 0 2009-12-21 14:58 test2
-rw-r--r-- 1 root root 0 2009-12-21 14:58 test5
[email protected]:~#

server2.example.com:

ls -l /data/export

[email protected]:~# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2009-12-21 14:58 test4
[email protected]:~#

server3.example.com:

ls -l /data/export

[email protected]:~# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2009-12-21 14:58 test6
[email protected]:~#

server4.example.com:

ls -l /data/export

[email protected]:~# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2009-12-21 14:58 test3
[email protected]:~#

 

Falko Timme

About Falko Timme

Falko Timme is an experienced Linux administrator and founder of Timme Hosting, a leading nginx business hosting company in Germany. He is one of the most active authors on HowtoForge since 2005 and one of the core developers of ISPConfig since 2000. He has also contributed to the O'Reilly book "Linux System Administration".

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