Georedundancy in a data center: Maximum reliability for your IT infrastructure

In today's digital world, where companies depend on the virtually uninterrupted availability of their IT infrastructure, the concept of geo-redundancy in data centers is becoming increasingly important. Geo-redundancy refers to the distribution of IT resources across several geographically separate locations in order to ensure seamless availability in the event of local failures such as natural disasters or technical problems. The German Federal Office for Information Security (BSI) has drawn up a comprehensive list of criteria for this, which was updated and revised again in 2024. It specifies a minimum distance of 200 km for geo-redundant data centers. However, the document also offers the possibility of reducing these distances if there are technical reasons for doing so. As a colocation provider, EMC Home of Data operates geo-redundant data centers that offer maximum security, availability, and efficiency. In addition to its own locations in Munich and Rosenheim, EMC Home of Data, together with its strategic partners Pfalzkom Manet and IGN, provides solutions tailored specifically to geo-redundancy requirements at numerous locations in Germany. Thanks to excellent connectivity and cloud connections, these solutions can be adapted to the respective security requirements of each project.

What is geographic redundancy in data centers and why is it important?

Geo-redundancy describes the location redundancy of data centers, which is achieved by distributing data and applications across at least two physically separate locations. This prevents a single event, such as a power outage or fire, from crippling the entire IT system.

Advantages of geo-redundancy

• Greater reliability: Systems remain functional even in the event of large-scale disruptions.
• Improved data availability: Data loss is minimized through synchronous or asynchronous replication.
• Compliance with legal requirements: Many industry standards, such as ISO 27001, NIS2, and DORA, emphasize the importance of redundancy.

Availability classes and their significance for data centers

Data centers are classified based on their target availability, with a distinction made between highly available and maximum availability:

• High availability: Target availability of 99.99 % per year. This corresponds to a maximum tolerable downtime (MTD) of around 52 minutes per year.
• Maximum availability: Target availability of 99.995 % per year. This corresponds to an MTD of around 26 minutes per year.

These high levels of availability require targeted measures such as redundant systems, optimized infrastructure, and strict security concepts. EMC Home of Data offers data centers and solutions that range between Tier III and Tier IV levels. Thanks to geo-redundancy, even very high availability requirements can be met at almost Tier IV standard.

Tier-classifications (Uptime Institute)

1. Tier I – Basic infrastructure

• Availability: approx. 99.671%
• Maximum downtime per year: up to 28.8 hours
• Features:
  - Simple configuration (no redundancy, “single path”)
  - Maintenance and modifications usually lead to interruptions

2.Tier II – Redundant Capacity

• Availability: approx. 99.741% to 99.749%
• Maximum downtime per year: up to approx. 22 hours
• Features:
  - Redundant components (N+1)
  - Single supply path (single path)

3. Tier III – Redundancy + continuous maintenance

• Availability: approx. 99.982%
• Maximum downtime per year: approx. 1.6 hours
• Features:
  - Redundant components (N+1)
  - Two supply paths (at least one active)
  - Maintenance can be performed without interruption
  
  

4. Tier IV – Fault-tolerant infrastructure

• Availability: approx. 99.995%
• Maximum downtime per year: approx. 26 minutes
• Features:
  - Full fault tolerance (2× (N+1))
  - Two active supply paths (“dual path”)
  - Maintenance and failures of individual components do not affect operation

Classification and practical relevance

• Highly available solutions (99.99%) often move toward Tier III.
• Maximum available solutions (99.995% or higher) largely correspond to Tier IV.
• EMC Home of Data offers data centers between Tier III and Tier IV, including geo-redundancy, which can withstand even a complete failure of individual locations in an emergency.

The Tier classification thus provides important guidance for the selection and planning of data centers. Companies with particularly critical requirements should consider using a data center that meets at least the Tier III standard—or even Tier IV if necessary—to ensure continuous availability even in extreme situations.

Relevant natural disasters for geo-redundant data centers in Bavaria

River flooding

Bavaria is characterized by numerous rivers such as the Danube, Isar, and Inn, which is why flooding can pose a significant threat. To minimize the risk, the following applies:

• Within a river system, a maximum of one data center per geo-redundancy group may be operated.
• Notwithstanding this, additional data centers may be operated in the same river system if they are located at least 5 meters above the highest flood level since 1960.

Earthquake

Earthquakes pose a lower risk in Bavaria due to its location in earthquake zone 1, but they should still be taken into account in site planning. The most important requirements are:

• Geo-redundant data centers should be located in earthquake zone 1 at most.
• The minimum distance between data centers in the same zone is 200 km to minimize the probability of simultaneous damage.

Legal requirements and standards for geo-redundant data centers

NIS2 and DORA: New challenges and opportunities

The European standards NIS2 (Network and Information Security Directive) and DORA (Digital Operational Resilience Act) set new benchmarks for IT security and operational resilience in companies. These regulations underscore the importance of geo-redundancy as part of a holistic security strategy.

• NIS2: This directive requires critical infrastructures such as data centers to implement strict security and redundancy measures to minimize disruptions and ensure continuous availability.
• DORA: DORA broadens the focus on digital resilience and requires financial services providers and other regulated sectors to implement resilience strategies, including geo-redundancy.

EMC Home of Data ensures that all solutions can be operated in full compliance with these legal requirements, thereby meeting the highest standards for security and availability.

Challenges and EMC Home of Data solutions in implementing geo-redundancy

Efficient data replication

• Flexible use of synchronous and asynchronous replication depending on requirements.
• Optimized network connections that also include cloud services thanks to high connectivity.

Costs of geo-redundancy

• Cost-effective rack and cage solutions.
• Tier 3+ backup data center offering high availability at optimized costs.

Sustainability and future prospects

• Use of energy-efficient technologies to minimize the carbon footprint.
• Use of green electricity and innovative cooling solutions to combine sustainability with high resilience.

Conclusion

Geo-redundancy in data centers is not a luxury, but a necessity for companies that want to remain successful in a digitalized world. EMC Home of Data offers comprehensive solutions for geo-redundant data centers that guarantee maximum security and flexibility. With strategic locations, state-of-the-art technology, and an experienced project team, EMC Home of Data sets standards in terms of availability and resilience.