CentOS-3 csgfs combines both the Cluster Suite 3 (CS) and the Global File System 6.0 (GFS) into a single directory (csgfs). This makes it convenient if you use both but you can still use just the CS or the GFS on their own as you require.
The manual for these products can be found in the rh-cs-en-3-2.noarch.rpm and rh-gfs-en-6.0-4.noarch.rpm packages.
Please remember that CentOS provides community support via the firstname.lastname@example.org mailing list, forums and irc.
If you need payed up support then CentOS csgfs is probably not for you.
You do not need extra hardware to use this software. Without hardware like shared storage and fencing equipment you may not receive all the benefits that this software can deliver.
Updates to this software often lag significantly behind the core CentOS updates. For this reason you should take appropriate measures to protect the security of your servers which are using CentOS csgfs.
You can find CentOS csgfs under the centos/3/csgfs/i386/ directory of your favorite CentOS mirror. Yum headers are provided so you can easily integrate with the standard CentOS package management tools.
Depending on your fencing method, you may require an extra perl module perl-Net-SSLeay. This can be obtained from Dag/RpmForge.