Introduction

Having a plan in the event of an IT emergency/OT is already a first step, but the second step, which is just as important, is to review this plan. This second step is often neglected because people are comfortable and don't always feel the need to go the extra mile. However, in this day and age where technology moves so fast, these contingency plans can quickly become outdated and you don't realize it until it's too late. Disaster Recovery Testing (DiRT) offers an effective solution to avoid such problems.

This blog first shows some Disaster recovery-strategies in order to better understand the context. Various types of DiRT are then explained and some best practices are presented at the end. 

Disaster recovery strategies 

Disaster recovery is a strategy for quickly restoring systems and data after an incident. To achieve this, the strategy must have clear guidelines. Each strategy must be individual and adapted to each company. There are various approaches for this.

1. backup strategy
The backup strategy involves backing up data on a regular basis. This can be done either on-site or off-site. The advantage of off-site backups is that they are protected against physical damage on site, but access to on-site backups is faster.

2. hot, warm and cold sites
Hot, warm and cold sites differ in terms of access to the backups. Hot site is the most expensive, but also the fastest option for accessing data in an emergency. Applications that have a high RTO (Recovery Time Objective) requirement are best suited to the hot site strategy. Warm site is a partially equipped site that can be activated with lead time. Cold site is the most cost-effective, but also the slowest option. It is suitable for systems, applications and data that do not need to be available within a very short time.

3. Cloud-based Recovery
Companies can of course also move their applications and data to the cloud. The cloud has many advantages, such as scalability, fast recovery and the company's independence of location compared to the cloud.

4 RTO, RPO and resources
Basically, the choice of strategy depends on these three points.
- RTO (Recovery Time Objective): How quickly must systems be restored?
- RPO Recovery Point Objective: How much data loss is acceptable?
- Resources: What is financially and organizationally feasible?

Disaster recovery testing

A disaster recovery plan is only useful if it is up to date and constantly adapts to changes. DiRT is used precisely to optimize the plan. The first question is why DiRT is so important.

• Recognize weak points
• Update outdated plans
• Improve responsiveness
• Meeting regulatory requirements
  
  

DiRT includes various types of recovery tests:

• Tabletop test: This is a theoretical exercise in which you go through the disaster scenario with a team and check whether the plan is complete and feasible.
• Simulation test: The recovery procedures are to be tested here without affecting production systems.
• Failover testIn this test, production is intentionally redirected to a backup system to check whether the failover processes are working.
• Full-scale test: This is a comprehensive test in which the entire disaster recovery plan is implemented in a realistic scenario.
  
  

However, there are also some challenges with DiRT. Depending on the size of the company, the complexity can be very high, making it impossible to plan for all scenarios. Another issue is acceptance and the resources required: these tests require time, personnel and, in some cases, additional infrastructure. Such investments must first be approved by superiors. It is therefore all the more important that line managers understand the need for DiRT.

Best practices

Here are the best practices for optimizing your disaster recovery strategy.

• Regular testing: Depending on the size of the company and its complexity, more or less testing may be required, but once a year should be standard. A combination of the above-mentioned tests should be used.
  
• DocumentationAdapt the documentation every time systems and applications are changed. Clear instructions are needed in the documentation to prevent misunderstandings.
  
• Team training: Train the team involved to avoid mistakes and have a prepared team.
  
• Automations: Automate backup restores or failover simulations to increase efficiency. A monitoring tool should be used to track the progress of the test.
  
• Scenario-based planning: Realistic scenarios that are specifically adapted to the company are the best way to learn. It is also important to address the things you have learned after the test and discuss the mistakes. This has the greatest learning effect.
  
• Define roles and responsibilitiesEvery employee must know their role in the event of a disaster. Clear communication ensures that everyone is aware of their responsibilities. This is essential to avoid chaos and shorten response times.
  

Conclusion

A disaster recovery plan is the first step for companies to protect themselves against IT/OT failures. But making sure that plan works is the responsibility of disaster recovery testing. By using best practices such as documentation, training, automation and realistic scenario planning, companies can increase their resilience.

DiRT is not a burden, but an investment in the future security of a company. It not only strengthens the IT infrastructure, but also the confidence of employees, customers and partners in the company's ability to be prepared for unexpected events. After all, if you are prepared, you remain capable of acting - even in a crisis.