A Brief Introduction to Raid Classifications

RAID stands for a Redundant Array of Disks, because it places multiple hard drives together to surpass the technology of a single hard drive. The classification a person chooses will determine not only a computer’s speed, but will create a single drive using multiple drives. Thanks to the advanced storage technology, a company or individual can reduce the possibility of data loss whilst boosting their computer’s performance.

As mentioned, there are a variety of RAID classifications, with each class having a different purpose and impact on a computer’s performance. You must therefore choose a classification carefully to ensure you pick the right RAID class for your requirements.

To help you decide, we are offering a brief introduction on RAID classifications from 0 to 5.


Raid Class 0’s blocks are striped providing an excellent storage virtualization technology that features two disks or more. However, it does not feature any redundancy, so you will lose all your data if you lose a disk. RAID classification 0 provides no mirroring, which is why you should avoid opting for this class if you are looking for a critical system.


There will be at least two RAID class hard drives when you select RAID class 1. The technology features blocks that are mirrored, so the redundancy will ensure you will not lose data should one of the drives experience a failure. It is therefore suitable for critical systems.


RAID 2 is no longer available due to its slow performance and inefficiency. The technology offered a bit level strip, which was known as Bit Interleave Data Striping, which worked a little bit like RAID 0.


RAID 3 can be rather slow in its performance, because it is unable to handle multiple data requests at one time. The class uses a byte level striping, offering consecutive bytes on additional drives. RAID 3 is similar to RAID 2, because it uses every drive to perform an operation and it is therefore an unpopular storage option for many businesses.


RAID 4 seemingly offers the best parts of RAID 2, as it offers bit level striping, as well as dedicated parity. However, unlike RAID 2, RAID 4 can simultaneously process multiple requests and it does not need to distribute data across each drive to perform an I/O operation. Users can therefore benefit from a faster operation, which is why it has become a popular storage option.


Using a minimum of three disks, RAID level 5 features striped blocks with excellent redundancy thanks to the distributed parity. If you are seeking a R/W operation, it is important to note that the write options maybe slow, whilst the read options will more than likely be faster.

Whatever the RAID classifications you choose, you must be aware that it is not impossible to suffer from a RAID failure – and it should never be used as a backup substitute. In the event of a failure, it is recommended you contact an experienced RAID recovery team for a system restoration.

About the author Ian Dixon:
Ian Dixon is a Microsoft MVP (Most Valuable Professional), founder of TheDigitalLifestyle.com tech site and producer of the weekly The Digital Lifestyle Show podcast. Ian has been writing and talking about Windows for over 10 years and has over 20 years in IT as an IT Manager. Ian has thousands of followers on Twitter and Facebook and over 4 million views on his YouTube channel.
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