The GFS Shared File System provides to access and update a file system on a shared disk device from multiple nodes simultaneously. The GFS Shared File System maintains consistency in updating from multiple nodes to files or file systems. The file lock function spanning nodes can be used with a conventional API.
In this way, applications at multiple nodes can perform exclusive updating of mutual file data and reading of the latest data. A conventional UNIX file system API, such as file lock, can do these operations.
Figure 1.5 Distributed execution of file related application
