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.
Unison is a file-synchronization tool for Unix and Windows. It allows two copies of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other. Unison can deal with updates to both replicas of a distributed directory structure. Updates that do not conflict are propagated automatically. Conflicting updates are detected and displayed. Unison can communicate through a direct socket link or through an rsh/ssh tunnel. It uses network bandwidth efficiently.
This program runs stat(2) or lstat(2) on each input file and displays the results. By default, stat displays all the attributes returned by stat(2) or lstat(2). Specific attributes can be requested by specifying one of the command-line options. For better integration with scripting languages, the normally human-readable output can be forced to simple, numeric output with a command line option. This utility is inteded to be both command line and output compatible with the utility of the same name on SGI's Irix operating system.
scponly is an alternative "shell" of sorts for system administrators who would like to provide access to remote users to both read and write local files without providing any remote execution priviledges. Functionally, it is a wrapper around the ssh suite of applications. It is typically used by creating a user whose shell is set to scponly. This user can neither login interactively nor execute commands remotely, but it can use scp and sftp to download and upload files to the computer, governed by the usual Unix file permissions.