GlusterFS is a distributed file-system capable of scaling to several petabytes. It aggregates various storage bricks over Infiniband RDMA or TCP/IP interconnect into one large parallel network file system.
Refer below url to upgrade GlusterFS from its earlier versions to GlusterFS 3.5 version.
[upgrade to 3.5](http://www.gluster.org/community/documentation/index.php/Upgrade_to_3.5)