When you look at some of the installation documents for any of popular Linux distributions, you will see only few mentions of the term RAID, typically with passages such as "you will need RAID only if you are a very professional systems administrator and you already know what are you doing."

Even in the latest documentation of the latest Linux releases, this is likely the only thing you will see about RAID. This is one big reason why I think we should move past this barrier and demonstrate that RAID can be used by "normal" people.

RAID stands for "Redundant Array of Inexpensive Disks." This seems to be rather self-explantory, except for that strange word "inexpensive." In reality, it's usually just refers to common PC hard disks, either SCSI and IDE.

But some additional explanation is necesary, however. Array simply means multiple units. It is perhaps the most significant term in the acronym--for owners of just one, even huge, hard drive, RAID is absolutely useless. Also, the word "redundant" is not an entirely descriptive label. As you'll see, it is not as easy as that.

First, let's begin by describing what RAID can be.

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