RAID Redundancy: how it works

Here you will find out:

• what is redundancy

• redundancy in RAID 0 and 1

• when DiskInternals can help you

Are you ready? Let's read!

Understand what redundancy is and how it matters when choosing a RAID array to set up for your need.

What is Redundancy?

In simple terms, Redundancy refers to having multiple disks perform the same function(s). It is a critical factor in RAID storage technology; RAID, which is the acronym for Redundant Arrays of Independent Disks, is a type of storage virtualization technology where multiple disks are interconnected to perform a similar function.

Redundancy helps for fault tolerance, whereby, even though one of the disks in a RAID array fails, the array would still be functioning well, and the user(s) can still access files and data saved on the RAID virtual storage. There are different types of RAID arrays that exist.

RAID Array Levels & How They Work

There are many RAID array levels that exist; the commonest ones include RAID 0, RAID 1, RAID 01, RAID 10, RAID 5, and RAID 6. Each of these RAID levels have unique advantages and disadvantages, as well as requires different setup procedures.

However, RAID storage centers on three factors - Stripping, Mirroring, and Parity. These factors are pretty endemic to three RAID levels, namely, RAID 0, RAID 1, and RAID 5, respectively.

RAID 0 (Data Stripping)

RAID 0 is a RAID array level based on "Data Stripping." This means that data saved on RAID 0 array is stripped - split into data blocks and written/copied to multiple disks on the array. You can set up RAID 0 using two or more disks of different sizes; however, data is saved to the disk with the smallest size. While RAID 0 promises faster speeds and better performance, it does not support redundancy, parity, and fault tolerance.

Raid 1 (Data Mirroring)

In RAID 1 storage technology, the same data is saved across the connected disks. That is to say, as you save data, the data is replicated - in the same form - across the multiple disks used in the RAID array.

RAID 1 copies and mirrors data blocks across multiple drives, which makes it possible to still have access to your file even after one or two disks fail in the array; this is referred to as "Fault Tolerance."

Raid 5 (Parity)

Unlike RAID 0 and RAID 1, RAID 5 uses "parity drives" in addition to the other drives in your array. You need at least 3 drives to set up RAID 5, whereby two of the drives would work for data storage while the third drive is used as the "Parity Drive." The Parity drive in RAID 5 uses the XOR function and offers fault tolerance.

RAID Redundancy: Pros & Cons

The primary purpose of RAID storage is to achieve higher data storage efficiency, faster speeds, and fortification against sudden drive failures. However, RAID does not entirely eliminate the need for making data backups because RAID disks can still fail abruptly.

Also, RAID drives cannot prevent ransomware, malware, viruses, and or human errors. But then, when a RAID array is about to fail, it would show you signs. So basically, the benefits of RAID include fast speed, fault tolerance, parity, and bigger storage space, while the disadvantage is that it does not replace regular backups and files can get lost from RAID drives.

Redundancy vs. Backup

RAID offers redundancy, which refers to some level of protection against single/multiple disk failure. On the other hand, backup means saving a copy of your data in another disk, so that when your primary storage disk fails or gets corrupted, you can get back your important files from the secondary disk where the backup copy was saved.

In RAID, there are still chances that all the disks in the array could fail at the same time, which means there'd be no way to recover your files. But with backups, your data and files are saved in a "safe haven" and can be easily accessed when there's a need for that.

More so, backups can be saved in external storage drives such as external HDD, flash drives, SD cards, etc. There are even applications that allow you to back up to the Cloud, so you can access your data from any device at any time. You can decide on a backup routine: daily, weekly, monthly, or annually.

However, it is best to back up regularly, especially if you deal with new data and files every day; this will minimize the chances of completely losing your files.

Redundancy and Backup are two different things; hence, even thou you set up a RAID storage, endeavor to backup your files on the array, routinely, to another separate drive. Interestingly, DiskInternals RAID Recovery software comes with a built-in feature that allows the users to back up their RAID drives as "Disk Images."

Backup: Pros & Cons

Backup has many advantages to offer - mainly, it helps you get back all your important files in any case of data loss.

Pros:

• Protects your data against malware attacks, ransomware, virus attack, data theft, and human errors.

• Keeps your data handy - as you can save backup copies on portable, removable drives such as flash drives and external hard drives.

• Data backup applications are typically free, or fairly priced.

• Backup copies never fail, but RAID drives can fail.

Cons:

• If the drive where you saved the backup gets corrupted, your files are gone; however, you could use a “Data Recovery” solution to get them back.

Protect Your Data - Create Back UPs

RAID does not in any way substitute backup, regardless of the type of RAID setup you decide to create. Whatever you're doing on a computer system, it is important to create routine backups.

There are many software applications out there that allow you to make backups; however, DiskInternals RAID Recovery software lets you do it for free, and it actually creates “Disk Images.” These disk images serve as the backups of the selected hard disk.

RAID Failure Prevention Tip

RAID failures cannot be entirely avoided, but here are some prevention tips that may be of help.

• Always monitor the RAID disk drives’ critical SMART parameters, health status, and temperature routinely. This will help you identify RAID array failure signs earlier and fix them before it escalates.

• Always back up your data regularly because no one can be too sure when data loss could occur.

• Don’t perform CHKDSK or SFC scans in a bid to fix and repair RAID array errors.

• Don’t ever use the “beta” version of a RAID firmware, OS, or system file. However, ensure to keep your OS and critical software apps updated to their latest stable versions regularly.

Reserve at least two new or empty drives to use in replacing failed drives in an array.