Cloud Storage Guide – Everything you need to know in one place

Cloud storage: The Guide for businesses

Q: What is cloud storage?

Cloud storage refers to the storage of data on a cloud provider’s remote servers, which can be accessed via the internet or an API. Businesses rent exactly the capacity they need – scalable, with redundant storage, and billed according to usage.

Q: What is the difference between object storage and block storage?

Object storage stores data as objects in flat buckets via an HTTP API (S3) – it offers unlimited scalability and is ideal for backups, media and archives. Block storage is mounted as a drive and offers the lowest latency – ideal for databases and VM disks.

Q: What does ‘S3-compatible’ mean?

S3-compatible storage utilises the Amazon S3 API, which has become the industry standard, and works with the same tools, SDKs and backup programmes – without the need for any code changes. This makes migrating from AWS S3 to a German provider straightforward.

Q: Is cloud storage suitable as a backup destination?

Yes – object storage is the ideal backup destination thanks to its scalability, versioning and low costs. At centron, it can be combined with cBacks for automated backups and cProtect for immutable snapshots to protect against ransomware.

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.

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The three types of storage

Object storage, block storage or file storage – what is the difference?

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.

A comparison of storage 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 · month)	Volumes (€0.05/GB · month)	Can be implemented via VM + volume

Cloud Storage Comparison

A comparison of cloud storage for businesses: what matters

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

Transparent invoice

How much does cloud storage cost for businesses?

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.

€0.02 / GB · monthS3 Object Storage · free external traffic

S3 pricing in detail

1 TB of backups/archives ≈ €20 per month for object storage – delivery included
Database volume: 100 GB = €5 per month for NVMe block storage, charged by the hour
No escape trap – Migration and downloads incur no additional charges
Automatic backup – can be combined with cBacks as a backup destination

Storing data in a legally compliant manner

Is cloud storage GDPR-compliant?

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.

Encryption

Transmission via TLS, storage with server-side encryption – access only via your S3 access keys and granular bucket policies.

Location: Germany

Our own data centre in Hallstadt near Bamberg – your data never leaves Germany and is governed exclusively by German and European law.

AVV & Supporting Documents

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 attestation).

Versioning & Immutability

Object-based versioning protects against accidental overwriting; cProtect provides immutable recovery points to guard against ransomware.

The checklist

How do you choose the right cloud storage provider?

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.

Get some no-obligation advice

Total cost, including traffic? Calculate storage cost + requests + egress
S3-compatible API? Standard tools and libraries work straight away
Data location & legal framework? Germany/EU, no access from third countries
Any evidence? ISO 27001 (IT-Grundschutz), C5 attestation, AVV pursuant to Article 28 of the GDPR
Scaling & limits? Growth is possible without changing contracts
Support? Experts on hand, no need to queue for a ticket – at centron 24/7

Cloud Storage FAQ

Frequently Asked Questions about Cloud Storage

What is cloud storage?

Cloud storage is the storage of data on a cloud provider’s remote servers, which can be accessed via the internet or an API. Instead of buying and maintaining their own storage hardware, businesses rent exactly the capacity they need – scalable, fail-safe thanks to redundant storage, and billed according to actual usage.

What is the difference between object storage and block storage?

Object storage stores data as objects with metadata in flat buckets and is accessed via an HTTP API (S3) – it is virtually infinitely scalable, making it ideal for backups, media and archives. Block storage divides data into blocks and is integrated into an operating system as a drive – offering the lowest latencies, making it ideal for databases and VM disks. Rule of thumb: unstructured bulk data → object; performance-critical application data → block.

How much does cloud storage cost for businesses?

At centron, S3 Object Storage costs €0.02 per GB per month (minimum charge of €5 for 250 GB), with external traffic free of charge – meaning one terabyte costs around €20 per month. NVMe block storage costs €0.05 per GB. With hyperscalers, request and egress charges are added to the storage price; for data-intensive applications, these can account for the largest share of costs.

Is cloud storage GDPR-compliant?

Yes, provided that the data is stored within the EU, a data processing agreement in accordance with Article 28 of the GDPR is in place, and the provider is not subject to the legislation of a third country. Exercise caution with US providers: The US CLOUD Act can also compel access to European servers. centron stores data exclusively in its own German data centres and is an owner-managed German company with no US parent company.

What does ‘S3-compatible’ mean?

S3 is the object storage API established by Amazon, which has become the industry standard. An S3-compatible storage solution such as that offered by centron can be used with the same tools, SDKs and applications (such as rclone, s3cmd, Veeam or backup software) – without any code changes. This also makes migrating from AWS S3 to a German provider straightforward.

Is cloud storage suitable as a backup destination?

Yes – object storage is the ideal backup destination due to its scalability, versioning and low costs. At centron, customers combine S3 object storage with cBacks for automated daily backups; cProtect complements this strategy by providing ransomware protection with immutable snapshots and failover within seconds. The Disaster Recovery guide explains how it all works together.

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