Why not use a shared file system in a SAN versus NAS for servers that need file sharing?
Professor Poelker: Actually, that’s where the industry is heading. A GFS (Global File System) is currently under development by Microsoft for the Windows platform (via Longhorn). There are already multiple solutions on the market from other OS vendors (Sun’s SAMfs, IBM’s, storage tank), and a few for Linux. You can buy these solutions today, but they are proprietary. When all the OS vendors finally get together and agree on a standard for storage based Global file systems, it will become more prevalent and much cheaper. Chapter 2 Question: How does parity work? Is it data or information about the data? How can data be “recovered” from parity? Professor Poelker: Parity works by using a mathematical formula (usually an exclusive OR operation) on the data before it is stored on the disks. RAID (redundant array of independent disks) works by storing the data in chunks across all the drives in the “raid set.” The parity information (the result of the mathematical formula applied to the data
