What is data centre security?

Posted on in

Every click, payment, and digital handshake we make today depends on a hidden network of data centres quietly running in the background. Businesses, governments, and even mundane online services, such as shopping and banking, all rely on these facilities’ ability to keep their mission-critical systems running and online. When something does go wrong, whether it’s an outage or a breach, the impacts are not minor. Companies can endure damaging financial and reputational hits that linger for years, and even legal exposure.

Cybersecurity may dominate the limelight, but physical security forms the bedrock of data centre security. The best firewall in the world won’t save you if someone can walk in and tamper with equipment. Selecting a secure data centre is, then, not just about digital defence; it is about the building’s infrastructure, the personnel who secure it, and the processes that keep it operational.

In this post, we’ll delve into what data centre security entails, the threats it faces, how data centre tiers impact resilience, the physical security layers involved, and discuss digital security, as well as best practices.

What is data centre security and why does it matter?

At its core, data centre security is about guarding the infrastructure that enables modern life. It’s the set of tools, policies and procedures that help maintain a system’s security, balancing ease of access for the right people and overall integrity of data and networks. It allows a business to focus on its core operations.

The responsibility is shared. The data centre provider secures the physical environment: perimeters, monitoring, back-up systems and compliance to demanding standards. Clients, on the other hand, are responsible for locking down their racks, hardening their systems, and managing their data securely. For the whole picture to be viable, both sides must play their part.

The first and most basic line of defence, however, is the physical layer. Without it, logical and governance measures fall apart. It’s as if you constructed a house with the most secure locks and the best alarm system you could afford, and then left the front door open while you were at work, on holiday, or asleep in your bed. That’s like physical security in the digital world.

Resilience and uptime are also key. A secure data centre is not only about keeping people out, but about keeping systems available and operational. For businesses, that continuity is everything. Strong security and high availability go hand in hand, with leading facilities designed for maximum uptime through redundant power, cooling, and network systems.

Threat landscape for data centres

A range of risks threaten data centres, and understanding them helps explain why layered security is so important.

Of these, the physical threats are the most apparent. Theft, vandalism, or unauthorised access may result in hardware theft or damage, and lost data. A determined attacker doesn’t need to hack anything if they can just walk away with a server.

Cybersecurity threats are even more stealthy but no less destructive. Ransomware assaults, DDoS activities and insider abuse can all disrupt services. Robust physical security is also surprisingly crucial here; by preventing unauthorised access to your critical systems, you remove many of those cyberattack routes at the source.

Operational threats round out the picture. Human error might come in the form of a mistake, as shown above, but also a misconfiguration, a power outage, or an accident. The most optimal technology is only as good as the people and processes overseeing it.

No single defence can protect against every threat. That is why layered security, multiple barriers, physical and digital, is the only way to reduce risk to an acceptable level.

Understanding data centre tiers and their role in security

Data centres are not all made the same, and one way to measure their resilience and security is with the Uptime Institute’s Tier Classification System. While the system does not directly measure cyber or physical security, it is an important indicator of how well a facility can maintain availability and support business continuity.

  • Tier I data centres are the most basic, with limited redundancy. They deliver around 99.671% uptime, which sounds high, but actually allows for up to 28.8 hours of downtime per year.
  • Tier II adds some redundancy, bringing downtime down to around 22 hours annually.
  • Tier III takes resilience to the next level, offering 99.982% uptime, which translates to approximately 1.6 hours of downtime per year.
  • Tier IV facilities are the gold standard, with complete fault tolerance. They promise 99.995% uptime, equating to just 26.3 minutes of downtime annually.

The higher the tier, the more solid the engineering, the greater the redundancy, and the better the contingency against surprises.

Why does this matter for security? Because continuity and resilience are part of it. A Tier I data centre will be less expensive; however, the risk of downtime dramatically increases. The Tier IV facility is built to keep running even if the equipment cannot, or requires maintenance. Thus, tiers serve as an abbreviation not just for reliability, but also for fault containment.

Tiers is not just a list of features; it’s a business continuity measure indicating how well your data centre can protect your operations.

data centre tiers

Physical and building security layers

Physical defences underpin data centre security. Guards, barriers and locks have a role, but are most effective when backed up by strong policies, environmental safeguards and compliance frameworks. The Datum Data Centre Security Checklist is a great way to ensure that every aspect of your security measures is fulfilled. Here are the biggest ones.

Perimeter defences

Security begins at the edge. High fencing, electronic locks and reinforced gates keep vehicles and intruders out. There are security guards and every angle is covered by CCTV, which records feeds that are relayed back to a security operations centre (SOC) at our Manchester site. Biometric scanners and mantraps add an extra layer of security; only individuals who have been verified can proceed.

Building security

Once within the perimeter, the building is a fortress in its own right. Data halls don’t have windows, and only a few doors to minimise the risk. Multi-factor access is a given: a swipe card on its own won’t suffice; you’ll need to follow it up with some form of biometric scan, depending on the centre’s system, and then proceed through a mantrap.

Inside, racks and cages are anonymised to reduce their allure, with entry via physical locks. Key storage is tamper-proof, and there is a transparent chain of custody for every action.

Activity is kept under 24-hour surveillance, and security teams monitor for abnormalities. On some ultra-secure sites (like our Manchester campus), CCTV systems are directly fed into the on-site Security and Operations Control Centre (SOC), and the police-linked alarm receiving centre triggers an immediate emergency response.

Environmental resilience

However, physical security isn’t just about keeping people out; it’s also about safeguarding infrastructure from environmental hazards. Fire suppression systems detect and contain fires early, preventing them from spreading.

Other critical environmental systems, such as cooling within the data halls, are designed with redundancy in mind, ensuring temperatures remain within optimal ranges in the event of individual cooling unit failures. This also extends to power options like backup generators and multiple power feeds, which are capable of keeping systems operational during power outages

Compliance and standards

Finally, compliance underpins it all. Data centres that comply with ISO 27001 operate with solid information security management and PCI DSS for payment card data, demonstrating robust governance frameworks. NSI Gold approval means compliance with the UK’s highest security standards as audited by the National Security Inspectorate. Uptime Institute standards validate the redundancy pledged by the tier system. Together, these systems offer confidence that best practices are neither alleged nor assumed but are independently audited.


data centre security

Data centre security best practices

Security works best when built on three legs of a stool: people, process and technology. This is what best practices look like in actual data centre operations:

  • People: employees are trained to be on the lookout for anything unusual and must follow strict access procedures. Role-based permissions and activity logs are used to address insider threats.
  • Process: regular physical drills and disaster recovery simulations prepare teams for emergencies. Make sure that partners meet the same standard. The system is regularly audited to ensure compliance and to identify any additional requirements.
  • Technology: tech is one of our best defences, from environmental sensors to access control systems. But it will only work well when supported by good people and good processes.

The foundation of data centre security

Data centre security is built on layers, but at the very foundation sits physical protection. Without fences, guards, cameras, and resilience measures, the rest simply doesn’t hold up. Logical safeguards and compliance frameworks add vital strength, but they depend on a secure physical foundation.

Proper security is about resilience, trust, and compliance working hand in hand. With threats evolving, data centres must keep adapting their physical and digital layers alike. The good news is that today’s facilities are engineered with precisely that in mind, so the data driving our daily lives remains safe, secure, and with maximum operational uptime.

Back to Insights