High-Availability Storage With GlusterFS On Fedora 12 - Automatic File Replication (Mirror) Across Two Storage Servers - Page 2
On this page
3 Setting Up The GlusterFS Client
client1.example.com:
There's a GlusterFS client rpm package for Fedora 12, but the problem with it is that you will get errors like df: `/mnt/glusterfs': Software caused connection abort or df: `/mnt/glusterfs': Transport endpoint is not connected when you try to access the GlusterFS share. That's why we build the GlusterFS client from the sources to avoid these problems.
Before we build the GlusterFS client, we install its prerequisites:
yum groupinstall 'Development Tools'
yum groupinstall 'Development Libraries'
yum install libibverbs-devel fuse-devel
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
[root@client1 glusterfs-2.0.9]#
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 Feb 19 2010 19:20:46
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@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 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 replicate type cluster/replicate subvolumes remote1 remote2 end-volume volume writebehind type performance/write-behind option window-size 1MB subvolumes replicate 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
[root@client1 ~]# mount
/dev/mapper/vg_server3-lv_root on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/etc/glusterfs/glusterfs.vol on /mnt/glusterfs type fuse.glusterfs (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/vg_server3-lv_root
29G 2.5G 25G 10% /
tmpfs 248M 0 248M 0% /dev/shm
/dev/sda1 194M 23M 161M 13% /boot
/etc/glusterfs/glusterfs.vol
29G 2.5G 25G 10% /mnt/glusterfs
[root@client1 ~]#
(server1.example.com and server2.example.com each have 29GB of space for the GlusterFS filesystem, but because the data is mirrored, the client doesn't see 58GB (2 x 29GB), but only 29GB.)
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
Now let's check the /data/export directory on server1.example.com and server2.example.com. The test1 and test2 files should be present on each node:
server1.example.com/server2.example.com:
ls -l /data/export
[root@server1 ~]# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test1
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test2
[root@server1 ~]#
Now we shut down server1.example.com and add/delete some files on the GlusterFS share on client1.example.com.
server1.example.com:
shutdown -h now
client1.example.com:
touch /mnt/glusterfs/test3
touch /mnt/glusterfs/test4
rm -f /mnt/glusterfs/test2
The changes should be visible in the /data/export directory on server2.example.com:
server2.example.com:
ls -l /data/export
[root@server2 ~]# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test1
-rw-r--r-- 1 root root 0 2010-02-22 16:53 test3
-rw-r--r-- 1 root root 0 2010-02-22 16:53 test4
[root@server2 ~]#
Let's boot server1.example.com again and take a look at the /data/export directory:
server1.example.com:
ls -l /data/export
[root@server1 ~]# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test1
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test2
[root@server1 ~]#
As you see, server1.example.com hasn't noticed the changes that happened while it was down. This is easy to fix, all we need to do is invoke a read command on the GlusterFS share on client1.example.com, e.g.:
client1.example.com:
ls -l /mnt/glusterfs/
[root@client1 ~]# ls -l /mnt/glusterfs/
total 0
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test1
-rw-r--r-- 1 root root 0 2010-02-22 16:53 test3
-rw-r--r-- 1 root root 0 2010-02-22 16:53 test4
[root@client1 ~]#
Now take a look at the /data/export directory on server1.example.com again, and you should see that the changes have been replicated to that node:
server1.example.com:
ls -l /data/export
[root@server1 ~]# ls -l /data/export
total 0
-rw-r--r-- 1 root root 0 2010-02-22 16:50 test1
-rw-r--r-- 1 root root 0 2010-02-22 16:53 test3
-rw-r--r-- 1 root root 0 2010-02-22 16:53 test4
[root@server1 ~]#
5 Links
- GlusterFS: http://www.gluster.org/
- Fedora: http://fedoraproject.org/
