5 Simple Reasons Why RAID Is Not a Backup


“Can I use RAID in place of backups?” I see this question posted throughout the web in one form or another. After learning how RAID facilitates redundancy, prevents data loss, and improves uptime you may start to wonder: why not? We’ve got a couple good reasons, but first let’s brush up with some basics.

One of These Things is Not Like the Other

Perhaps the easiest way to draw a line between these two concepts is to familiarize ourselves with redundancy. Backups, as we know, create copies of your original data so that you can recover the data in the event of a disaster. Redundancy, the driving force behind RAID, aims to provide continuity no matter the weather. Be it at the network or data level, redundancy makes it so no single point of failure can bring your operation to a halt. While redundancy enables it to contribute to business continuity, disaster recovery is where RAID falls short.


Now that we’ve got the technical stuff out of the way, let’s dive into some specific examples that illustrate why RAID can’t fill backup’s shoes.

1. RAID Can’t Stop Malware

Malware has many faces, but none is causing ruckus quite like ransomware. The classic virus overwrites your files and brings your system to a crawl until you remove the infection. Ransomware essentially holds your system hostage until you pay to regain access. Unfortunately, this sort of infection strikes so fast that it renders anti-virus software powerless. RAID can prevent disruptions, but it cannot keep your system up and running when ransomware takes hold. Next to prevention, a good backup strategy is the only way around paying the ransom and avoiding significant downtime.

2. RAID Can’t Eliminate Human Error

RAID is a proven effective way to mitigate downtime caused by hardware failure. However, it is ineffective when human error comes into play. According to a recent study championed in tandem by Ponemon Institute and Emerson Network Power, human error is responsible for 22 percent of data center outages. This percentage has not changed since the 2013 version of this study, suggesting that something is still amiss when it comes to employee education. If an employee accidentally deletes company data, backup copies kept on or offsite are the only option for recovery.

3. RAID Can’t Mitigate Onsite Disasters

Disaster in the data center is something we’d prefer not to think about. The mere thought is depressing. Dreadfulness aside, every organization should plan to combat unplanned downtime. A flood, hurricane, or fire can sweep through without warning and literally destroy everything in the data center – RAID controllers and backups included. The most reliable way to mitigate disaster in your facility is to not only backup, but commit to an offsite backup strategy that allows you to recover in a worst case scenario.

4. RAID Can’t (usually) Prevent File Corruption

Most RAID configurations have built-in safeguards that prevent data loss in the event of hardware failure. RAID has well documented data protection capabilities, but it is not a fail-safe solution for data corruption. As we discussed in a previous post, RAID can actually make matters worse by replicating the damage throughout the array. Even a good backup plan may be challenged if copies of the corrupt files are made. The one saving grace is that conducting regular backups increases the likelihood of being able to restore your files to a point before corruption occurred.

5. RAID Redundancy Has Its Limitations

While the entire RAID concept is based on redundancy, there are scenarios in which a backup can do a better job of it. In fact, the ideal backup plan is redundant by nature. It’s strongly recommended to keep copies of mission-critical data in at least two separate locations. For example, you can protect against fires and other onsite disasters by storing copies of your files in a different data center and another copy in the cloud. Spreading those copies across different regions would protect against even bigger issues. This redundant approach to backup is the best possible way to ensure business continuity.

If you’ve been thinking of depending on RAID as your one and only data protection solution, remember this: RAID will help mitigate most system failures. Backup will allow you to roll back time when failure can’t be prevented. Instead of going the do or die route of choosing one or the other, you can get even better results by doubling down with both and giving yourself an added peace of mind.