Cloud Disaster Recovery

An IT infrastructure failure is a serious problem for companies that requires quick action. That is why it is best to prepare an appropriate response in advance. One possible solution is cloud disaster recovery. Read on to find out more about the cloud recovery concept, how it differs from other strategies, and what to look out for when making the switch.

Cloud Disaster Recovery or Cloud DR for short refers to an emergency backup strategy for data, applications, and hardware that, unlike conventional approaches, relies on storage in the cloud. In the event of a failure, the affected data, applications, and other resources can be restored from the cloud at the touch of a button so that business can resume as quickly as possible. Service providers now offer Disaster Recovery as a Service (DRaaS).

The core component of cloud DR emergency backups form digital images of relevant data and configurations to be used as temporary replacements (especially for hardware) and as a point of reference for recovery in the event of an emergency. Since these images are stored in the cloud or an external data centre, companies that rely on cloud disaster recovery are on the safe side in the event of local crisis situations such as fires, floods, or earthquakes.

In principle, disaster recovery can exist without the cloud. Business-critical resources can be protected in-house using classic approaches for disaster recovery. Traditional disaster recovery differs from cloud disaster recovery concepts in three aspects:

1. Complexity and maintenance effort
2. Costs and flexibility
3. Security

A crucial difference between cloud DR and classic DR is the effort associated with setting up and maintaining the necessary hardware and software for backup and recovery. Companies that opt for a cloud DR plan benefit from technologies being outsourced which means they don’t need to be set up and administered on a company’s premises. In addition, the provider renting out the cloud resources typically oversees complex interactions of the individual components and the maintenance of the hardware.

This, in turn, reduces the cost of cloud disaster recovery because businesses don’t need to procure expensive hardware and require minimal staff to manage the recovery solution in the cloud. There are also no follow-up costs for defective and obsolete hardware. If more resources are needed, they can be conveniently added at any time.

The third advantage of cloud DR is the high security standard provided by cloud service providers or software houses, which not only encompasses digital security of the data – achieved through security and encryption software – but storing data in external data centres also provides for better protection against on-site data theft, natural disasters, or fires.

There are three basic approaches to building a cloud disaster recovery solution: Cold Cloud DR, Warm Cloud DR, and Hot Cloud DR. The names in no way represent the temperatures maintained within these system architectures, but merely indicate the ease with which they can be implemented.

Cold cloud-based disaster recovery typically involves the simple storage of data or images of virtual machines. These resources are ‘cold’ in the cloud and are unusable without an intermediate step because the data or images must first be downloaded and integrated in the event of recovery.

On the one hand, cold cloud DR is the easiest and most cost-effective approach to implement. On the other hand, these architectures tend to have a relatively high downtime. These pros and cons should be weighed up from a business perspective.

Warm cloud DR is a standby approach in which mirrors of all mission-critical data and applications are stored with a provider. The duplicated resources are always kept up to date, but no data processing takes place. In the event of a disaster, the mirrored infrastructure can be used for recovery.

A certain amount of downtime is therefore unavoidable. Nevertheless, warm cloud disaster recovery makes for fast data recovery. Complexity and costs are higher compared to the cold approach.

The highest level of complexity in terms of cloud disaster recovery is the hot approach. Here, the entire workload and all of a company’s data are distributed not only across the company's internal IT infrastructure, but simultaneously across the resources of the cloud DR provider. Data processing is live and takes place across both sites. If one site fails due to a disaster, all IT processes can continue without interruption thanks to the remaining, unaffected site.

Hot Cloud DR is the only architecture with no downtime, but this comes at a price. The cost of the two complete infrastructures running in parallel is significantly higher than a cold or warm DR framework.

Whether locally or in the cloud, a disaster recovery plan that is optimally tailored to the needs of the company is not forged overnight. When planning business continuity, choosing the right partner is not the only issue. We have summarised some useful tips to help you make the transition to a disaster recovery plan in the cloud.

Even if you hand over most of the responsibility and management effort to a provider with a cloud DR solution, you still need people within the company to oversee the planning and maintaining of data protection. Trained personnel who are aware of their tasks and duties are therefore essential for an efficient cloud disaster recovery strategy.

It must be clearly defined in which cases a cloud DR comes into play. Is the solution already required for when certain applications fail or individual data is lost? Or does ‘disaster’ refer to classic catastrophes such as earthquakes, flooding, fires, and the like?

The choice of provider plays an important role in cloud DR. Companies need to consider many factors that extend far beyond typical factors such as costs or contractual terms. On the one hand, the selected provider should meet data protection and security requirements, like the GDPR. The availability of additional services is another decisive factor. For example, if you prefer to keep efforts to a minimum, a Managed Service Provider that offers the complete DRaaS package is the best solution.

Many companies tend to rent hardware and software resources from a single provider in order to keep track of their rented services. But this makes them heavily dependent on the provider. You should keep this so-called ‘lock-in’ effect in mind when selecting your cloud disaster recovery (and when choosing other new cloud services).

In the best-case scenario, you won’t ever have to draw on your cloud DR plan. But this shouldn’t be assumed. It is a good idea to test your cloud disaster recovery concept in advance in cooperation with your provider to avoid any issues or insecurities as to whether your plan will work when an incident arises.