Although they are completely different things, I tend to have the same basic philosophy for disaster recovery as...
I do for security: defense in depth. For decades, security professionals have been taught that there is no single solution that will provide comprehensive security across an entire organization. Instead, security professionals use a wide variety of security products and techniques. A good data recovery plan should involve just as much effort.
The idea behind defense in depth is that, if the bad guys manage to get past one of the organization's key defenses, then there are other mechanisms in place to help thwart the attack.
So, with this in mind, let's talk about data and disaster recovery (DR). DR can best be described as the ability to keep mission-critical systems running following some sort of disaster. This can be anything from something simple, like a disk failure, to a catastrophic event, such as a fire or a hurricane. Just as there are a wide variety of potential security breaches, catastrophes requiring a data recovery plan can also come in all shapes and sizes.
When it comes to DR, there is a natural tendency to focus on major disasters. As such, a data recovery plan in preparation for disaster is often based around the idea of replicating virtual machines (VMs) to a remote data center or to the cloud so that those resources can be activated when needed.
While these types of contingency plans are undeniably important, there is something else that needs to be considered. Disasters do not conform to any sort of widely accepted IT model. There are a huge variety of disaster types that can range from inconvenient to catastrophic. A disaster can be anything from a brief power failure to a nuclear blast. Just as there is a wide variety of disasters, there is also a wide variety of methods to protect and recover data in the event of one.
RAID as a DR tool
One example of a technology that can help bolster a data recovery plan is RAID. RAID does not often make its way into discussions of DR, but that doesn't mean it can't be of some assistance. RAID is designed to do two main things: improve storage performance and guard against disk failure. When it comes to DR, RAID can help in a couple of different ways.
First, RAID can provide redundancy. Not all RAID configurations use redundancy, but those that do can store data redundantly to prevent disk failures from turning into complete outages. After all, it's always better to prevent a disaster than to cope with one.
A second way in which RAID can help is by achieving the highest possible storage I/O. The availability of storage I/O is often the limiting factor when it comes to hosting VMs. When VMs are activated as part of a DR effort, this can spell trouble.
Today, most backup applications feature an instant recovery option that enables VMs to be run directly from the backup, while a recovery operation happens in the background. Using RAID to achieve the highest possible storage I/O capacity on your recovery systems may enable those systems to host a greater number of VMs than would otherwise be possible, thereby helping you to better cope with various disasters.
Just as it is important to base cybersecurity efforts on the concept of defense in depth, it is also important to base a data recovery plan around the use of different mechanisms. Not every disaster warrants performing a large-scale failover to the cloud, and unorthodox data protection and recovery methods may come in handy when least expected.