The 3-2-1 backup rule is now standard: three copies, two media, one offsite. The “offsite” piece for many SMBs today lives at an S3-compatible cloud provider — because it integrates effortlessly with TrueNAS Cloud Sync, Proxmox Backup Server and Veeam. But which provider? Backblaze B2, Storj, Wasabi and AWS S3 are the four heavyweights; each has a different profile. We don’t deliver a price list — those change monthly — but an evaluation matrix with criteria to help an SMB choose in a structured way.

Why S3-compatible?

S3 isn’t only an Amazon service but the de-facto protocol for object storage. All common backup tools (Veeam, Borg, Restic, Duplicacy, TrueNAS Cloud Sync, Proxmox Backup Server 4.x+) speak S3 — which concretely means:

Multi-vendor strategy: B2 today, Wasabi tomorrow, your own MinIO cluster the day after — backup tooling doesn’t change
Object Lock: S3 Object Lock enables immutable backups (ransomware protection)
Replication: cross-region replication is a built-in standard
Versioning: S3 automatically keeps versions (when enabled)

Anyone picking a provider that only speaks a proprietary protocol (classic “online backup providers”) is effectively bound to that tool — switching later gets expensive.

The four providers at a glance

Backblaze B2

Model: pure cloud storage provider, one of the pioneers of cheap object storage
Locations: US-West, US-East, EU (Amsterdam)
Geo-redundancy: within a region via erasure coding across multiple data centers
Egress: first 3× of stored data per month free to the internet, billed beyond
Minimum retention: none
API: native B2 API plus S3-compatible layer
Strength: very simple pricing, one of the cheapest options on the market
Weakness: limited region choice, no German location

Storj

Model: decentralized storage network — files are split into erasure-coded fragments across hundreds of nodes
Locations: globally distributed, geofencing selectable (e.g., “EU only”)
Geo-redundancy: structurally built-in via erasure coding across multiple nodes/regions
Egress: flat per GB, often cheaper than classic providers
Minimum retention: none
API: native Storj API plus S3-compatible gateway (Storj S3 Gateway)
Strength: very high redundancy by architecture; iX-Storj is the TrueNAS-specific Storj variant with seamless TrueNAS web-UI integration
Weakness: conceptually unusual — anyone who wants “one data center” as a target is conceptually wrong here

Wasabi Hot Cloud Storage

Model: S3-compatible “hot storage” — no tier distinctions, no lifecycle management
Locations: US, EU (Amsterdam, Frankfurt, London, Paris, Milan), APAC
Geo-redundancy: per region
Egress: no egress charge (very unusual on the market!)
Minimum retention: 90-day minimum storage time — files deleted earlier are still billed for 90 days
API: S3-compatible
Strength: no egress = predictable cost, especially during frequent restores; Frankfurt location available
Weakness: the 90-day minimum is a show-stopper for short-lived backups (e.g., build artifacts)

AWS S3 / S3 Glacier

Model: hyperscaler with full AWS integration; storage classes Standard / IA / Glacier / Deep Archive
Locations: worldwide, eu-central-1 (Frankfurt) and eu-central-2 (Zurich) for EU workloads
Geo-redundancy: three AZs per region for standard storage; cross-region replication optional
Egress: per GB with tiered volume discounts
Minimum retention: none for Standard; Glacier 90 days, Deep Archive 180 days
API: S3 (the original)
Strength: full maturity, compliance certificates (BSI C5, ISO 27001, etc.), deepest AWS integration
Weakness: tends to have the highest list price, complex pricing with many variables

Evaluation matrix

Criterion	Backblaze B2	Storj	Wasabi	AWS S3
Price (storage, ballpark)	Cheap	Very cheap	Medium	High (Standard) to very cheap (Glacier DA)
Egress cost	Free up to 3×, then medium	Flat per GB	None	Per GB, tiered
EU location	Amsterdam	Geofencing possible	Frankfurt, more EU	Frankfurt, Zurich
DACH compliance	Solid	Via EU geofencing	Solid	Very comprehensive
S3 Object Lock	Yes	Yes	Yes	Yes
Minimum storage time	None	None	90 days	0 (Standard) / 90 / 180 days
Glacier-class	No, uniform class	No, uniform class	No, uniform class	Yes (Glacier IR / DA)
TrueNAS integration	Standard	iX-Storj native	Standard	Standard
API maturity	Very good	Mature S3 compat since 2024	Very good	Reference
Multi-region within provider	Medium	Structural	Good	Very good

Important: concrete dollar amounts per TB-month fluctuate at all four providers. We deliberately don’t quote them here — they would be stale by publication. Instead, the price lists are linked directly:

Three typical SMB scenarios

Scenario A: daily server backups, rare restores

Volume: 5 TB
Restore frequency: 1× per quarter for testing, 1–2× per year for real
Retention: 90 days daily, 12 months monthly

Recommendation: Wasabi or B2. Wasabi drops egress charges — good for rare restores that tend to be large. B2 is slightly cheaper on pure storage but charges egress on restores. Both offer Frankfurt/Amsterdam in the EU.

Scenario B: Veeam M365 backup with frequent item-level restores

Volume: 2 TB
Restore frequency: multiple times per week (single mails/calendar items)
Retention: 7 years, tamper-resistant

Recommendation: AWS S3 with lifecycle to Glacier IR after 30 days. Hot tier for recent mail (fast item-level restores), Glacier IR for older — the tiered model plays to its strengths here. Alternative: Wasabi, if the 90-day minimum is tolerable.

Scenario C: TrueNAS replication as a second offsite rail

Volume: 50 TB
Restore frequency: rare, worst case “data center gone”
Retention: TrueNAS snapshot chain

Recommendation: Storj / iX-Storj. The decentralized architecture provides structural redundancy, the per-TB price is competitive, the TrueNAS integration is native. For very large data volumes a comparison with AWS S3 Glacier Deep Archive pays off — it is unbeatably cheap for rarely accessed data.

What really drives the choice

From our advisory practice:

Restore frequency is the most important factor — frequent restores make egress the dominant cost line
EU location is non-negotiable as soon as personal data or professional confidentiality is in play
API maturity matters — we have hit edge cases on newer S3 implementations that didn’t pair ideally with classic backup tools
Minimum storage time is the most frequent trap for buyers who anchor “cheap” only on the storage price
Compliance certificates are formally needed by few SMBs but reassuring during audits

Configuration tips

Enable Object Lock — at least “Governance Mode” for 30 days as ransomware protection
Use lifecycle policies — automatically push old versions to cheaper tiers (especially on AWS)
Bucket versioning — without it, an accidental “delete backup” has catastrophic effect
Multi-factor delete — decisive safeguard against compromised API keys
Client-side encryption — even if the provider encrypts, client-side is the clean variant

DATAZONE recommendation

We usually set up cloud backup for our customers with a multi-provider strategy: a primary provider matching the workload and location, a secondary one (for critical data) at a different provider in a different region. That guards not only against hardware failures but also against vendor insolvencies or API incompatibilities after a provider update.

Cloud Backup Providers Compared: B2, Storj, Wasabi, AWS