Introduction to Linux Cluster Filesystems

Traditionally, a cluster is simply a group of servers, either PCs or workstations, acting as a single system. That definition is stretching considerably, however; cluster technology is now a dynamic field with diverse applications that is continually absorbing new features. Furthermore, cluster filesystem technologies, whether open source or proprietary, are rapidly converging in their capabilities. More accurately, most clusters have two main components: servers, which are connected to some sort of shared storage media through a fast network, and filesystems, which act as the software "Glue" that keeps the cluster nodes working together. This paper takes a high-level look at differences among cluster filesystems in general and some of the characteristics of the Oracle Real Application Clusters (RAC) environment specifically.