When most people think of file systems, they think in terms of a single computer system spanning one or more disks or storage subsystems. Given the tendency to manage increasing amounts of data, vendors are offering what can be called "global file systems", where the file system spans multiple computers in a distributed network. Sistina's Global File System (http://www.sistina.com/products_gfs.htm) is one example of this category, but there are examples for Linux such as Software.Linux.com's GFS 5.1, which is a 64-bit shared-disk cluster file system.
GFS is a high performance solution that allows you to replicate data among nodes (even on heterogeneous systems), providing high availability, load balancing, cluster support, and file-system abstraction. This abstraction lets you continue to add storage devices (even with heterogeneous storage devices), provides a single management console for your domain, and can make it easier to run your network applications on commodity hardware. For example, Sistina has its GFS running in front of Oracle 9i with direct I/O support, offering scalability advantages over straight Oracle clusters, the company says.
IBM has a GFS (they call it GPFS, where "P" stands for parallel) white paper on its Web site at: http://www-1.ibm.com/industries/media/resource/.
Barrie Sosinsky is president of consulting company Sosinsky and Associates (Medfield MA). He has written extensively on a variety of computer topics. His company specializes in custom software (database and Web related), training and technical documentation.
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