Kernel korner: storage improvements in 2.6 and for 2.7
Paul E. McKenney · Linux journal · 2004
The advent of FibreChannel (FC) in the mid-to-late 1990s improved this situation considerably. Although compatibility was and to some extent still is a problem, the multi-kilometer FC lengths greatly simplified datacenter layout. In addition, most of the FC-connected RAID arrays export logical units (LUNs) that can, for example, be striped or mirrored across the underlying physical disks, simplifying storage administration. Furthermore, FC RAID arrays provide LUN masking and FC switches provide zoning, both of which allow controlled disk sharing. Figure 1 illustrates an example in which server A is permitted to access disks 1 and 2 and server B is permitted to access disks 2 and 3. Disks 1 and 3 are private, while disk 2 is shared, with the zones indicated by the grey rectangles.