What is RAID and what you need to know about RAID

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If you’ve ever spent any time either building computers or working with them, then you will have come across the term RAID. But what exactly does it mean? And when might you want to use it? 

What Is RAID?

Raid stands for redundant array of independent disks (it used to mean a redundant array of inexpensive disks). It’s a protocol that allows you to link storage drives together to enhance performance in some way. It is not the same as NAS.

Each RAID has a coding, such as RAID 0, RAID 1, RAID 2, and so on, to delineate between the various configurations. Different schemes offer varying tradeoffs between four key metrics: capacity, performance, reliability, and availability. Typically, if you want more of one, you have to make do with less of the others.

Take RAID 0, for instance. In RAID 0, the capacity of the drives remains fixed. Information is coded onto each disk, allowing the CPU to access multiple drives simultaneously. RAID 0 speeds up access to information, helping data-heavy files and applications load faster. The downside is that if you lose data on one disk, then you lose it across all of them. RAID is, therefore, a risk-reward paradigm. In the example of RAID 0, you trade a higher risk of losing your data for faster load times.

RAID 5 is different. Here all parity information is distributed among all drives. If one storage device fails, the system can calculate what was on the disk, preventing the whole ensemble from losing any information. RAID 5, however, still suffers the same fate as RAID 0 if more than one drive fails. 

RAID configurations come in two varieties: software and hardware. In the software version, an app uses the processing power of the CPU to orchestrate data flows between various storage devices. In the hardware version, a physical RAID card plugs into a motherboard PCI-E slot and does all the heavy lifting. 

Why Do People Use RAID Arrays?

Raid arrays are a way of enhancing the performance of computer storage devices. There are, therefore, numerous reasons why you might want to use one.

Home computer enthusiasts, for instance, might decide to implement a RAID 0 array to make their games load faster. Companies, on the other hand, might need to operate fast storage servers because of a high level of network demand.

Companies often use RAID arrays to improve data security. RAID 6 allows companies to not only avoid catastrophe if one of their drives fails (as with RAID 5) but also hot-swap new drives if downtime isn’t an option.

The state-of-the-art (and the most expensive) RAID scheme is RAID 10. RAID 10 includes the best of both RAID 0 and RAID 1, offering both speed and an enormous amount of redundancy. The downside, however, is that it can be extremely costly. In most configurations, you need to install double the regular number of disks to make it work. It offers high performance disk-striping when you have many users, but it is usually only economically viable for the largest organizations.    


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