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Hornetsecurity S3 Storage Alternative: Ensuring GDPR Compliance and EU Data Sovereignty

26.02.2026

13

Minutes
Thomas Demoor
CTO Impossible Cloud
For MSPs, choosing the right S3-compatible storage is critical for data protection, cost predictability, and regulatory adherence in Europe.

Managed Service Providers (MSPs) are at the forefront of safeguarding client data. With cyber threats escalating and regulatory frameworks like the General Data Protection Regulation (GDPR) becoming increasingly stringent, the choice of cloud storage for backup solutions is more critical than ever. Many MSPs rely on robust backup software like Hornetsecurity VM Backup, which offers seamless integration with S3-compatible object storage for offsite and immutable backups. However, the underlying storage infrastructure can introduce complexities, particularly concerning data residency, compliance, and unpredictable costs.

This article explains why a dedicated Hornetsecurity S3 storage alternative GDPR compliant and based in the EU is a strategic necessity for European MSPs. We will explore the challenges posed by extraterritorial laws, the hidden costs of traditional cloud storage, and the benefits of a sovereign, S3-compatible solution that offers full control and cost certainty, ensuring your clients' data remains secure and compliant within European borders.

Key Takeaways

  • European MSPs must prioritise S3 storage alternatives that ensure GDPR compliance and EU data sovereignty, protecting client data from extraterritorial laws like the U.S. CLOUD Act.
  • Unpredictable egress fees and complex pricing models from hyperscalers can significantly erode MSP margins; a transparent, no-egress-fee model is crucial for cost predictability.
  • Impossible Cloud offers a sovereign, S3-compatible, and 'Always-Hot' object storage solution, providing EU-only data residency, predictable pricing, and robust Object Lock for ransomware protection, making it an ideal Hornetsecurity S3 storage alternative GDPR compliant for European MSPs.

The Evolving Landscape of Data Protection for European MSPs

Managed Service Providers in Europe navigate a complex web of data protection regulations, with GDPR at its core. The General Data Protection Regulation (GDPR) sets strict rules for how personal data is collected, processed, and stored, emphasising principles like data minimisation, storage limitation, and the integrity and confidentiality of data. For MSPs handling vast amounts of client data, ensuring compliance is not merely a legal obligation but a cornerstone of client trust and business reputation. Non-compliance can lead to significant penalties, as evidenced by record fines issued by European data protection authorities.

Beyond GDPR, other directives such as the NIS2 Directive (Directive (EU) 2022/2555) further expand cybersecurity requirements for critical entities and digital service providers, including cloud computing service providers and managed service providers. This means MSPs are increasingly responsible for implementing robust security measures, conducting thorough risk analyses, and having incident reporting processes in place. The supply chain security aspects of NIS2 also place an onus on MSPs to ensure their chosen cloud partners meet these stringent standards, making the selection of a compliant and secure S3 storage alternative even more critical.

The European Union's broader Digital Decade targets aim for 75% of EU enterprises to be using advanced cloud/AI services by 2030, driving growth in trusted data spaces. This push for digital sovereignty, coupled with the EU Data Act, which focuses on data portability and interoperability, underscores Europe's commitment to reducing dependence on foreign jurisdictions and enhancing control over digital assets. For MSPs, aligning with this strategic direction by choosing EU-based, GDPR-compliant cloud storage is a proactive step towards future-proofing their services and ensuring long-term client confidence.

Hornetsecurity's Backup Solutions and the Need for S3 Compatibility

Hornetsecurity is a well-regarded provider of backup and recovery solutions, offering products like VM Backup (formerly Altaro VM Backup) and 365 Total Protection. These solutions are designed to protect virtualised environments (Hyper-V, VMware, Proxmox) and Microsoft 365 data, providing features such as Continuous Data Protection (CDP), WAN-optimised replication, and robust ransomware protection.

A key component of Hornetsecurity's strategy for offsite backups and ransomware protection is its support for S3-compatible cloud storage. Hornetsecurity VM Backup, for instance, allows users to send redundant copies of their backups to various S3-compatible targets, including Amazon S3, Wasabi, Azure Blob Storage, and Backblaze B2. This S3 compatibility is crucial because it provides flexibility, allowing MSPs to choose their preferred cloud storage provider while leveraging Hornetsecurity's powerful backup capabilities. Furthermore, Hornetsecurity solutions can utilise S3 Object Lock, a feature that renders backup data immutable, protecting it from deletion or modification for a defined retention period, which is vital for ransomware defence and compliance.

While this S3 compatibility offers choice, it also places the onus on MSPs to carefully evaluate the underlying S3 storage provider. The choice of an S3 storage alternative directly impacts data sovereignty, cost predictability, and overall GDPR compliance. Simply having S3 compatibility is not enough; the storage solution itself must align with the stringent requirements of the European market, especially when dealing with sensitive client data.

The Imperative for EU Data Sovereignty and GDPR Compliance

For European MSPs, the concept of data sovereignty is paramount. It refers to the idea that data is subject to the laws and governance structures of the nation in which it is stored. While GDPR does not strictly mandate data localisation (i.e., keeping all data within EU borders), it imposes stringent conditions for transferring personal data outside the European Economic Area (EEA), requiring an 'adequate' level of protection.

The primary challenge to data sovereignty in the EU arises from extraterritorial laws, most notably the U.S. CLOUD Act. Passed in 2018, this act allows U.S. authorities to compel U.S.-based cloud providers to provide access to data stored anywhere in the world, regardless of its physical location. This directly conflicts with GDPR Article 48, which states that foreign court orders are only valid if based on an international agreement, such as a Mutual Legal Assistance Treaty (MLAT). Consequently, if an MSP uses a U.S.-headquartered cloud provider, even if the data is physically stored in an EU data centre, it remains potentially accessible by U.S. authorities without the consent of the data owner or European regulators. This creates a significant legal dilemma for EU businesses, as complying with a U.S. warrant could mean breaching GDPR.

To mitigate this risk and ensure full GDPR compliance, European organisations are increasingly seeking cloud providers that are exclusively subject to EU law. This 'Sovereign by design' approach means data remains within EU jurisdiction, free from the extraterritorial reach of non-EU laws. The European Commission has even introduced a Cloud Sovereignty Framework to measure the independence and security of cloud services operating in the EU, highlighting the strategic importance of this issue. For MSPs, choosing an S3 storage alternative that is genuinely sovereign is a critical step in protecting client data and maintaining legal certainty.

Evaluating S3 Storage Alternatives: Key Criteria for MSPs

When selecting an S3 storage alternative for Hornetsecurity backups, MSPs must look beyond basic compatibility and consider a range of factors that impact operational efficiency, cost, and compliance. The market offers numerous S3-compatible options, from hyperscalers like Amazon S3 and Azure Blob Storage to specialist providers. However, not all S3-compatible storage is created equal, especially concerning the unique demands of European MSPs.

Key evaluation criteria include:

Cost Predictability and Egress Fees

Hyperscaler cloud providers often employ complex pricing models that can lead to unpredictable costs. A major culprit is egress fees – charges incurred when data is transferred out of the cloud provider's network. For example, AWS S3 egress costs can be around $0.09 per GB for the first 10 TB, while Azure Blob Storage charges approximately $0.087 per GB after a 100 GB free tier. These fees can quickly accumulate, especially for backup and disaster recovery scenarios where large volumes of data might need to be retrieved or moved. For MSPs operating on tight margins, unpredictable egress fees can erode profitability and make accurate billing to clients challenging. A transparent pricing model without egress fees is a significant advantage.

Data Residency and Sovereignty

As discussed, the physical location of data and the jurisdiction it falls under are critical for GDPR compliance. An ideal S3 storage alternative for European MSPs should offer geofenced storage options within the EU, ensuring data never leaves the European Economic Area and is not subject to extraterritorial laws like the CLOUD Act. This provides legal certainty and simplifies compliance documentation.

Security and Immutability

Robust security features, including multi-layer encryption (in transit and at rest), Identity and Access Management (IAM) with Multi-Factor Authentication (MFA), and Role-Based Access Control (RBAC), are non-negotiable. Crucially, support for S3 Object Lock (WORM – Write Once, Read Many) is essential for ransomware protection, preventing backup data from being altered or deleted for a specified retention period.

Performance and Reliability

Backup and recovery operations demand high performance. An 'Always-Hot' object storage model, where all data is immediately accessible without tier-restore delays, is preferable. Strong read/write consistency, predictable latencies, and multi-AZ replication ensure data availability and rapid recovery in disaster scenarios.

MSP-Specific Features

For MSPs, features like a multi-tenant console, whitelabel capabilities, automation via API/CLI, and dedicated partner support are vital for efficient management and scaling of their Backup-as-a-Service (BaaS) offerings.

Comparison of S3 Storage Alternatives for European MSPs
Criteria Hyperscalers (e.g., AWS S3, Azure Blob) EU Sovereign S3-Compatible Provider
Data Residency & Sovereignty Global data centres, but U.S. CLOUD Act risk applies to U.S.-owned entities, even for EU-stored data. Potential GDPR conflict. EU-only data centres, geofenced storage, exclusively subject to EU law (GDPR, UK DPA 2018, NIS2). No CLOUD Act exposure.
Cost Predictability Complex tiered pricing, significant egress fees (e.g., $0.09/GB for AWS S3, $0.087/GB for Azure Blob), API call costs, minimum storage durations. Unpredictable monthly bills. Transparent, predictable pricing with no egress fees, no API call costs, and no minimum storage duration. Simplified budgeting for MSPs.
S3 Object Lock for Immutability Supported, but underlying provider jurisdiction still poses a sovereignty risk. Supported and enhanced by EU jurisdiction, ensuring WORM protection is legally robust within EU frameworks.
Performance Model Tiered storage (Hot, Cool, Archive) with potential retrieval delays and costs for less frequently accessed data. 'Always-Hot' object storage model, ensuring all data is immediately accessible without tier-restore delays. Predictable low latency.
MSP Business Model Support Generic cloud services, may require custom tooling for multi-tenancy and whitelabeling. Built for MSPs with multi-tenant console, RBAC, whitelabel options, and predictable margins.

Why a European S3 Storage Alternative Matters for Hornetsecurity Users

For MSPs utilising Hornetsecurity's robust backup solutions, the choice of an S3 storage backend is not merely a technical decision; it's a strategic one with profound implications for compliance, cost, and client trust. Opting for a European S3 storage alternative, especially one designed with sovereignty in mind, offers distinct advantages over traditional hyperscalers.

Firstly, it provides unparalleled GDPR compliance and legal certainty. By ensuring data is stored exclusively within EU data centres and governed solely by EU and UK laws, MSPs can confidently assure clients that their data is protected from extraterritorial access requests, such as those under the U.S. CLOUD Act. This eliminates the legal bind and reputational risk associated with using U.S.-based providers, even if their data centres are located in Europe. This commitment to EU-only options and geofenced storage simplifies the complex task of demonstrating compliance to auditors and clients alike.

Secondly, a European alternative often brings predictable and transparent pricing. Hyperscalers' variable costs, particularly their egress fees, can make budgeting a nightmare for MSPs. When backing up client data with Hornetsecurity, the need to restore or transfer data can trigger unexpected charges, eating into profit margins. A European S3 storage alternative that offers no egress fees, no API call costs, and no minimum storage duration provides a stable cost base, allowing MSPs to accurately forecast expenses and offer competitive, fixed-price services to their clients. This predictable by design approach fosters healthier, more sustainable MSP business models.

Finally, choosing a European S3 storage alternative reinforces digital sovereignty, aligning with the broader European Data Strategy. This not only enhances security and control but also supports the growth of a resilient European digital infrastructure, reducing reliance on non-European providers. For MSPs, this means partnering with a provider whose values and legal framework are inherently aligned with their own and their clients' needs in the European market.

Impossible Cloud: A Sovereign S3-Compatible Solution for MSPs and Hornetsecurity Backups

For Managed Service Providers seeking a robust, GDPR-compliant, and cost-predictable Hornetsecurity S3 storage alternative GDPR, Impossible Cloud offers a compelling solution. Built from the ground up as a European, S3-compatible object storage provider, Impossible Cloud is engineered to meet the stringent demands of data sovereignty and compliance for the EU and UK markets.

Impossible Cloud's infrastructure is operated exclusively in certified European data centres across Germany, the Netherlands, the UK, Denmark, and Poland. This commitment to EU-only options ensures that all data remains within European jurisdiction, providing full protection from extraterritorial laws like the U.S. CLOUD Act. With country-level geofencing, MSPs have granular control over where their clients' data resides, simplifying GDPR and UK Data Protection Act (DPA 2018) compliance. This 'Sovereign by design' approach delivers the legal certainty and peace of mind that European businesses require.

Beyond sovereignty, Impossible Cloud addresses the critical issue of unpredictable costs. Unlike many hyperscalers, Impossible Cloud operates with a transparent pricing model that includes no egress fees, no API call costs, and no minimum storage duration. This 'Predictable by design' philosophy allows MSPs to accurately calculate their costs and offer fixed-price Backup-as-a-Service (BaaS) solutions, significantly improving their margins and eliminating billing surprises for clients. This financial predictability is a game-changer for MSPs looking to scale their backup offerings profitably.

Furthermore, Impossible Cloud provides full S3-API compatibility, making it a true drop-in S3 replacement for existing backup solutions, including Hornetsecurity VM Backup. This means MSPs can seamlessly integrate Impossible Cloud as an offsite backup target without requiring any code rewrites or complex reconfigurations. The platform also supports advanced S3 features like Object Lock for Immutable Storage, providing essential ransomware protection by ensuring backup data cannot be altered or deleted for a defined period. Combined with 99.999999999% (11 nines) durability and an 'Always-Hot' object storage model, Impossible Cloud delivers enterprise-grade performance and resilience without compromise. MSPs can also benefit from a multi-tenant console with RBAC/MFA, automation via API/CLI, and whitelabel capabilities to launch their own branded cloud services. To learn more about how Impossible Cloud empowers MSPs, explore our customer success stories.

FAQ

Why is GDPR compliance a major concern for MSPs using S3 storage?

GDPR compliance is critical for MSPs because they process and store personal data on behalf of their clients. Choosing an S3 storage provider that adheres strictly to GDPR, including data residency within the EU and protection from extraterritorial access, is essential to avoid legal penalties and maintain client trust. Non-compliance can lead to significant fines and reputational damage.

How does the U.S. CLOUD Act affect EU data stored with U.S. cloud providers?

The U.S. CLOUD Act allows U.S. authorities to compel U.S.-based cloud providers to hand over data, regardless of where it is physically stored. This creates a direct conflict with GDPR, which requires international agreements for data transfers to non-EU authorities. Even if data is in an EU data centre, if the provider is U.S.-owned, it may still be subject to U.S. legal demands, compromising EU data sovereignty.

What are egress fees, and how do they impact MSPs?

Egress fees are charges levied by cloud providers for transferring data out of their network. For MSPs, these fees can be substantial and unpredictable, especially during data restores or migrations, directly impacting profitability and making it difficult to offer fixed-price services to clients. Providers with no egress fees offer greater cost predictability and margin stability.

Does Hornetsecurity VM Backup support S3-compatible storage with Object Lock?

Yes, Hornetsecurity VM Backup supports S3-compatible cloud storage and leverages S3 Object Lock for immutable backups. This feature is vital for ransomware protection, as it prevents backup data from being modified or deleted for a specified retention period, ensuring data integrity and recoverability.

What are the benefits of an 'Always-Hot' object storage model for backups?

An 'Always-Hot' object storage model ensures that all data is immediately accessible without any retrieval delays or additional costs associated with different storage tiers. For backups and disaster recovery, this means faster recovery times (RTOs) and consistent performance, which is crucial for minimising downtime and ensuring business continuity for clients.

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