How the RAID technology works?

Many people probably wonder what RAID is, and if you google it you will find all sorts of technical mumbo-jumbo about it. All might not be understandable for the common consumer. I will try to make couple of articles here that hopefully can make it a little bit more understandable.

First of all what is RAID?

RAID is a collection of multiple hard drives, and they are arranged into arrays to achieve redundancy. Redundancy means that you have all your data stored on drives, and if a drive fails you won’t lose any data. That is the key word about redundancy.

What does RAID mean?

In the beginning the acronym came up in 1987 which meant Redundant Array of Inexpensive Disks. And the first RAID I think was mirroring and it meant you could put cheap drives (may be not that reliable) into array and if one of the drives failed it didn’t lose any data. After a while the acronym was rewritten which now stands for Redundant Array of Independent Disks. Meaning that there is a lot of independent disks working together making storage array.

Why do we need RAID?

It is a cost effective storage if you need redundancy, and it give you increased performance in terms of read and write speed. All types are high performance but some of them do deliver higher reading speeds or writing speeds or both. Last and most important is Redundancy. For consumer today the most common types of RAID that are available is RAID 0 also known as stripped disks, and you have RAID 1 also known as mirroring or mirrored disks, and we have RAID 5 also known as Stripped disks with distributed parity.

What about JBOD?

Some people might want to ask about JBOD; why is JBOD in the list of common types of RAID? And that is simple because JBOD is Non-Raid architecture.

What do I need to make a RAID-array?

First of all what you need is a minimum of 2 HDD’s. Or else it’s going to be a single drive. Other requirement is that you have to have a RAID Controller. It could either be a hardware based controller built into your motherboard, or as a separate controller card PCI or PCI express, whatever and it can be software based meaning that perhaps operating system supports some types of RAID modes or architectures.

Windows XP and OS 10 offer both stripping and mirroring. I think Also OS10 offers JBOD but it’s not RAID as I mentioned and also there is a way to make windows XP or later windows versions offer you RAID 5. I am not sure if it’s standard now. But many years ago I read how you could change some files in windows XP and make it support RAID 5.

What type of RAID-mode or RAID-architecture is right for me?

That depends on three things:

  • It depends on how much your need for redundancy is and
  • how much money you can afford. Your performance need.

So it’s going to be a balance between your need for redundancy, high performance, and how much money can you put into it.
By the way no matter what kind of RAID array or RAID setup you’re using, it’s never ever replaced the need for backing up your files! So no matter what; always keep a backup of your files.