Raid - Redundant Array of Inexpensive or Independent Disks

RAID - Redundant Array of Inexpensive or Independent Disks

Introduction:

Back in the 1980's and early 1990's, business computing environments began to encounter substantial increases in the amount of data they needed to store. Because of cost, size, and speed, simply adding additional hard drives to physical servers to store this every increasing amount of data was simply not feasible. This was the computing environment in which the computer science department at UC Berkeley first developed the RAID concept. Today, RAID has become the standard storage feature in enterprise-class business environments because data must be available 24 hours per day and 7 days per week and data accessibility and reliability has become a key factor in the success of business. . But what is RAID, what does it do, how does it work, and what are its benefits and/or tradeoffs. This essay will attempt to answer these basic questions by providing an overview of RAID storage technology.

What is RAID?

So what exactly is RAID? It’s an acronym that stands for “Redundant Array of Independent (or Inexpensive) Disks” and like many advanced technologies, the concept behind it is actually quite simple. Technically, it is a data storage system that links together large numbers of inexpensive and/or independent hard drives to act as a single logical unit that then provides a mechanism to store the same data on the multiple hard drives. To put it another way, RAID can be thought of as an umbrella term for a computer storage system that, depending on the type of RAID configuration chosen, can divide and replicate data among multiple hard drives for the purpose of increasing data protection and data input/output (I/O) performance. Data is better protected because if a physical hard drive fails the data would not be lost because it exists on multiple physical hard drives. Additionally, by placing the data on multiple disks, I/O operations can overlap thereby improving performance. But how does...