Cloud storage is the storage of data on a cloud provider’s servers, which are accessible via the internet – rather than on local hardware. Businesses use three types of storage for this purpose: object storage for unlimited scalable data volumes, block storage for fast application data, and file storage for shared file repositories. This guide explains the differences, the costs and the criteria for choosing a provider – including a look at the GDPR.
Object storage stores data as objects with metadata in flat ‘buckets’ – it is infinitely scalable and ideal for backups, media and big data. Block storage divides data into blocks and offers the lowest latency – the right choice for databases and VM drives. File storage organises data into a familiar folder structure for shared network drives. Most organisations combine several types.
| Criterion | Object Storage | Block storage | File Storage |
|---|---|---|---|
| Structure | Objects in buckets (flat) | Blocks, mounted as a drive | Files in a folder hierarchy |
| Scaling | virtually unlimited | up to the volume limit, expandable | limited by the file system |
| Access | HTTP API (S3-compatible) | Operating system (as a disc) | Network protocols (NFS/SMB) |
| Latency | moderat | lowest (NVMe) | moderat |
| Ideal for | Backups, media, archives, data lakes, AI datasets | Databases, VM disks, transactional workloads | Shared folders, home directories |
| centron product | S3 Object Storage (€0.02/GB) | Volumes (€0.05/GB) | Can be implemented via VM + volume |
Consumer services such as Google Drive or Dropbox are designed for personal files – businesses need S3-compatible APIs, predictable costs and clarity regarding the GDPR. The biggest hidden cost factor with hyperscalers is outbound traffic (egress): anyone transferring or migrating large volumes of data pays per gigabyte with AWS and similar providers. With centron, external traffic in S3 Object Storage is free of charge.
| Criterion | Consumer services (Drive, Dropbox) | Hyperscalers (AWS S3 and others) | centron S3 Object Storage |
|---|---|---|---|
| Target audience | Individuals & small teams | Companies, global | Companies, Germany/EU |
| S3 API | nein | ja | Yes, fully compatible |
| Storage price | Subscription per user | per class, plus requests | €0.02 per GB, from €5 per month |
| Outgoing traffic | limitiert | subject to a charge (egress charges) | kostenlos |
| Data location | mainly USA/worldwide | eligible for election, US parent company | exclusively Germany |
| Legal framework | US CLOUD Act possible | US CLOUD Act possible | German/EU law only |
| Evidence | – | diverse | ISO 27001 (IT-Grundschutz), BSI C5:2020 Type 1 |
Business cloud storage is billed per gigabyte per month. At centron, S3 Object Storage costs €0.02 per GB (minimum charge of €5 per month for 250 GB) – including free external traffic. A terabyte therefore costs around €20 a month, with no hidden fees for access or data transfer. NVMe block storage for databases costs €0.05 per GB. By way of comparison: with hyperscalers, request and egress charges are added to the storage price, which can multiply the bill for data-intensive applications.
Cloud storage is GDPR-compliant if three conditions are met: the data is stored within the EU (preferably in Germany), there is a data processing agreement in accordance with Article 28 of the GDPR, and the provider is not subject to the legislation of third countries such as the US CLOUD Act – which applies to US parent companies even if the servers are located in Europe. centron stores data exclusively in its own German data centres (ISO 27001 (IT-Grundschutz), BSI C5:2020 Type 1) and is an owner-managed German company. For further details: Data sovereignty at centron.
Transmission via TLS, storage with server-side encryption – access only via your S3 access keys and granular bucket policies.
Our own data centre in Hallstadt near Bamberg – your data never leaves Germany and is governed exclusively by German and European law.
Data Processing Agreement in accordance with Article 28 of the GDPR, documented TOM and audited processes (ISO 27001 (IT-Grundschutz), unrestricted BSI C5:2020 Type 1 certificate).
Object-based versioning protects against accidental overwriting; cProtect provides immutable recovery points to guard against ransomware.
Six questions are the difference between choosing the right provider and making costly mistakes. Answering them before migration helps you avoid the two most common problems: skyrocketing egress costs and subsequent data protection disputes with customers or auditors.
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