Recently RedHat opensourced Global File System. The Global File System (GFS) is a 64-bit shared disk cluster file system for Linux. GFS cluster nodes physically share the same storage by means of Fibre Channel or shared SCSI devices. The file system appears to be local on each node and GFS synchronizes file access across the cluster. GFS is fully symmetric, meaning that all nodes are equal and there is no server which may be a bottleneck or single point of failure. GFS uses read and write caching while maintaining full UNIX file system semantics. GFS supports journaling, recovery from client failures, and many other features. Under my opensource project http://xfdeb.sourceforge.net/ I released the first unofficial deb kernel packages supporting Global File System on a 2.6.8.1 vanilla kernel and all the set of utilities for GFS clustering (GULM, CCS, etc).

Here Kernel packages and utilities and software .
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Angelo Ovidi
XFDeb Project