Utilizing RAID and RAIN

We have looked at so many ways of interfacing with our storage. But probably the most exciting is when we start to deal with RAID (Redundant Array of Inexpensive Disks) and by extension its descendant, RAIN (Redundant Array of Independent Nodes). Before we go too far, it must be noted that RAID is a huge topic that would require a book of its own to truly address in a meaningful way. Understanding how RAID works and all of the calculations necessary to understand the nuances of its performance and risk is a major subject all on its own. My goal here is to introduce the concept, explain how it fits into a design, expose the best practices around it, and prepare you for further research.

RAID and RAIN are mechanisms for taking many storage devices (block devices) and using the natural device multiplicity (often misstated as redundancy) to provide some combination of improved performance, reliability, or scalability over what possibility with only an individual...