GFS and GFS2 differ from distributed file systems (such as AFS, Coda, or InterMezzo) because it allows all nodes to have direct concurrent access to the same shared block storage. In addition, GFS and 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 is a separate module and 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.
来自 “ ITPUB博客 ” ，链接：http://blog.itpub.net/35489/viewspace-611413/，如需转载，请注明出处，否则将追究法律责任。