RAID (Redundant Array of Inexpensive Disks/Redundant Array of Independent Disks) exists as a way to combine multiple storage hard disks into a single array. Ingeniously, this vastly increases performance, capacity and availability or to ensure data redundancy. But how does RAID pull off so many feats?

First and foremost, the way in which RAID improves performance and availability is extremely intuitive.

RAID 0

By combining multiple hard disk drives into one unit, data is divided into blocks by spreading across multiple drives, such that data is being stored simultaneously. With multiple disks being able to constantly access the file, this greatly improves read/write speeds which aid greatly in performance.

RAID 1

Data is “mirrored” by storing it twice. In the case that a hard disk drive fails, data is effectively backed up and just has to be copied onto a replacement drive.RAID 5

A minimum of three drives are required to function. A parity is utilized in this RAID level, which essentially functions as a derived algorithm that one can use to obtain the other parts of the data. In RAID 5, it can tolerate up to 1 drive failure.

RAID 6

This RAID system has a higher tolerance level towards simultaneous failures compared to RAID 5. It consists at least 4 drives. As it will hold up to 2 parity in each drive, it will still work if 2 of your drives broken down.

RAID 10

The technology is a combination of RAID 1 and RAID 0. In essence, we are mirroring and stripping concurrently, as shown in the diagram below. Should something go wrong with one of the disks, the rebuild time is very fast since all that is needed is copying all the data from the surviving mirror to a new drive.

We will describe further about all these RAID in our coming blog.

EHDR, We Leave No Data Behind.