In computing, the Global File System 2 or GFS2 is a shared disk file system for Linux computer clusters. GFS2 differs from distributed file systems (such as AFS, Coda, or InterMezzo) because GFS2 allows all nodes to have direct concurrent access to the same shared block storage. In addition, GFS or GFS2 can also be used as a local filesystem.
GFS has no disconnected operating-mode, and no client or server roles. All nodes in a GFS cluster function as peers. Using GFS in a cluster requires hardware to allow access to the shared storage, and a lock manager to control access to the storage. The lock manager operates as a separate module: thus GFS and GFS2 can use the Distributed Lock Manager (DLM) for cluster configurations and the "nolock" lock manager for local filesystems. Older versions of GFS also support GULM, a server based lock manager which implements redundancy via failover.
GFS and GFS2 are free software, distributed under the terms of the GNU General Public License.
Read more about GFS2: History, Hardware, Differences From A Local Filesystem, Journaling, Features of GFS2 Compared With GFS, Compatibility and The GFS2 Meta Filesystem