Types of corporate data backups for security

Archiving and Long-Term Storage Are Not the Same

In everyday practice, the term "archiving" is often used to refer to any copy of information. However, there is an important distinction. A backup serves to facilitate rapid recovery following a system crash, user error, cyberattack, or hardware failure. Backups are created frequently and usually retain multiple versions of the data.

A long-term archive stores inactive information that must remain accessible for a specific period—such as accounting documents, contracts, correspondence, or records subject to regulatory requirements. While storage costs may be lower, such archives are not necessarily designed to restore an entire working environment within hours.

For a business, these two functions often need to operate in parallel. Documents from five years ago might reside in a long-term archive, while current files, virtual machines, and databases are protected by frequent backups.

Main Types of Corporate Data Archiving

The appropriate model depends on where the data is used, how rapidly it changes, and the cost of downtime. Rarely is the best solution a single type of copy stored in just one location.

Local Archiving

With local archiving, copies are stored on a device within the office or data center—such as a NAS system, a dedicated backup server, a disk array, or other secure storage media. Its primary advantage is speed. In the event of a large file deletion or server failure, recovery over the local network is usually significantly faster than downloading data via the internet.

The downside is the shared risk affecting both the primary system and the archive. Fire, theft, electrical issues, flooding, or a crypto-virus gaining access to network storage can affect both copies. Local backup is essential in environments with large data volumes and tight recovery time objectives, but it should not be the sole form of protection.

Cloud Backup

In this model, backups are sent to a secure cloud infrastructure or an off-site data center. This provides the company with an off-site copy without the need to invest in a second physical facility. Cloud storage enables automation, encryption, retention policy management, and easier scalability as data volumes grow.

Internet connectivity is a key factor here. The initial upload of several terabytes of data can be time-consuming, and full recovery following a major incident depends on available speeds. Specific terms must also be verified: where the data is stored, how access rights are managed, which versions are retained, and the actual scope of the service.

Hybrid Backup

The hybrid model combines a local copy for rapid response with an off-site copy for protection against large-scale incidents. This is a practical choice for most small and medium-sized enterprises. A file deleted in the morning can be restored from local storage almost immediately, while the off-site copy serves as a safeguard against issues affecting the building, infrastructure, or the entire local network.

The hybrid approach requires effective coordination. Having two destinations is not enough; it must be clear which systems are being copied, whether the tasks complete successfully, and whether the off-site copy is isolated from the production environment.

File and Folder Backup

This is the most recognizable type of backup. It involves copying specific file servers, shared folders, user data, and work documents. This approach is effective when the primary risk is file loss and when applications do not require a specialized recovery procedure.

The limitation is that restoring files does not automatically restore the operating system, settings, applications, and dependencies. If a key business process runs on a database server, a file-level backup alone may not be sufficient.

System and Virtual Machine Image-Based Backup

Image-based backup creates a copy of an entire system—including the operating system, applications, configurations, and data. In virtual environments, an entire virtual machine can be backed up and restored to the same or another compatible host. This significantly reduces downtime in the event of a server failure.

This type of backup requires more storage space and careful planning, but the benefit is clear: a functional environment is restored, not just individual documents. For accounting, ERP, CRM, or production servers, this often makes the difference between a brief interruption and days of manual reconfiguration.

Database and Application Backup

Databases change constantly and should not be treated like ordinary files. Copying a database at the wrong moment can result in incomplete or inconsistent data. Systems such as ERP, CRM, accounting software, and specialized applications require "application-aware backup"—a process that accounts for the service's state and ensures successful recovery.

Backup frequency should align with business risk. For an order-processing database, a nightly backup might result in unacceptable data loss. In such cases, more frequent transactional backups or replication are scheduled, balancing costs, system load, and acceptable risk levels.

Backing Up Microsoft 365 and Other SaaS Platforms

Files in SharePoint and OneDrive, Exchange Online emails, and Teams conversations constitute corporate data. There is a common misconception that the platform automatically retains every version indefinitely and protects against every user error. While the provider ensures service availability, the organization remains responsible for its own data, retention periods, and recovery processes.

Maintaining a separate backup of the SaaS environment provides control in scenarios involving accidental or malicious deletion, expired retention periods, departing employees, or the need to restore specific emails and files. This should be part of the overall backup strategy rather than excluded simply because the data resides "in the cloud."

Immutable and Isolated Backups Against Ransomware

Ransomware is no longer limited to standard work files. Attackers deliberately target backup servers, administrator accounts, and cloud storage to eliminate any possibility of recovery. Therefore, a secure backup setup must include at least one copy that cannot be modified or deleted for a predetermined period—an immutable copy.

Isolated copies that are not constantly accessible from the production network are also valuable. These could reside in a separate environment, on offline media, or in storage accessible only via strictly restricted credentials. Isolation does not eliminate the need for monitoring, but it significantly reduces the likelihood that a compromised administrator session could destroy all backups.

A practical starting point is the 3-2-1-1-0 rule: three copies of data, on two different types of media, one copy stored off-site, [one immutable or offline copy] (https://helpdesk.bg/en/blog/disaster-recovery-plan-for-businesses), and zero undetected errors following backup job verification. This is not a one-size-fits-all solution, but rather a risk-mitigation discipline.

Choosing the Right Strategy

Data classification should be performed before selecting a technology. Which systems are critical for revenue, customer service, and regulatory compliance? Which data contains personal information, trade secrets, or financial details? The answers to these questions determine priorities.

Next come two measurable objectives. RPO (Recovery Point Objective) indicates how much data a company can afford to lose—for example, up to one hour's worth of work. RTO (Recovery Time Objective) defines the maximum acceptable time for service restoration. A system with an RPO of 24 hours and an RTO of two days might require a different protection strategy than a system that must be back online within an hour.

Retention periods must also be defined. An overly short retention period could leave the organization without a clean version in the event of a breach discovered late. An overly long one increases costs and the risk associated with unnecessarily retaining personal data. The policy must align with GDPR, contractual obligations, and internal access rules.

An untested backup is merely an assumption

A successful backup job status does not guarantee that recovery will work. The file might have been copied, yet necessary permissions could be missing, the application might fail to launch, or the database might lack consistency. Regular tests should include restoring individual files, recovering email, verifying databases, and running periodic scenarios for entire critical systems.

Testing also provides a realistic view of recovery times. This transforms the RTO from a mere promise in a document into a verified operational metric. Results, gaps, and corrective actions should be documented, particularly for organizations subject to ISO 27001, GDPR, or NIS2 requirements.

A useful next step is to conduct a brief assessment of critical systems and determine the consequences should any of them fail tomorrow morning. Based on this specific picture, you can build a backup strategy that protects not just files, but the business's ability to continue operations.