Synology C2 Cloud Backup: In-Depth 2025 Review & Guide
Why Synology C2 Cloud Backup Matters in 2025
Ransomware, hardware failures, and accidental deletion still rank among the most common causes of data loss for individuals and businesses. Synology C2 Backup extends Synology’s well-known NAS ecosystem into the cloud, offering a tightly integrated backup platform for Windows and macOS endpoints, NAS devices, and Microsoft 365/OneDrive data.
Unlike generic cloud storage, Synology C2 is designed specifically for backup and disaster recovery. Its focus is full-system protection, versioned recovery, and strong security, rather than simple file syncing.
What Is Synology C2 Backup?
Synology C2 Backup is Synology’s cloud backup service, hosted in regional data centers and tightly integrated with its NAS and software ecosystem. It is available in plans for individuals and for businesses, with storage tiers typically ranging from a few hundred gigabytes up to several terabytes.
With C2 Backup, you can:
Back up entire Windows and macOS machines (bare-metal image backups)
Protect files and folders, including external drives.
Back up Microsoft OneDrive data and selected Microsoft 365 services
Store encrypted versions of your backups in Synology’s cloud
Restore full systems or granular files from any browser or C2 client
This makes Synology C2 a natural extension for existing Synology NAS users, but it can also be used even if you do not yet own a Synology NAS.
Key Features: Synology C2 Backup at a Glance
1. Full-System Image Backup
C2 Backup can capture the entire system: OS, applications, and data. This image-level backup allows you to restore a failed PC or server to a previous working state without rebuilding everything from scratch.
Benefits:
Fast recovery after ransomware or OS corruption
Consistent protection for workstations and critical endpoints
Bare-metal restore to new hardware with minimal downtime
2. File, Folder, and External Drive Protection
You can also protect individual volumes, folders, and external drives. When you connect an external drive, C2 can automatically detect and back it up based on your policies.
This is useful when:
You keep archives on USB drives or portable SSDs
You offload media projects or CAD files to external storage.
You need a secondary backup for local NAS volumes
3. OneDrive and SaaS Data Backup
Native integration with Microsoft OneDrive enables backup of cloud-hosted data that is often forgotten in traditional backup strategies.
Typical use cases:
Protecting Office documents stored only in OneDrive
Adding an independent backup layer beyond Microsoft’s retention policies
Reversing accidental or malicious deletion of cloud files
4. Strong Security and Privacy
Synology C2 encrypts data before it leaves your device, using client-side encryption. Only the encrypted data travels over TLS to Synology’s data centers, and the encryption keys remain under your control.
Security highlights:
End-to-end encryption of backup data
Transport security with HTTPS/TLS
Zero-knowledge design when you manage your own keys
Pricing, Value, and Limitations
According to independent reviews, Synology C2 typically scores highly for performance and value for money, especially when backing up full systems to the cloud. Storage plans generally scale from 500 GB up to several terabytes, with flexible monthly or annual commitments.
Strengths:
Excellent transfer performance for large backups
Simple pricing based on storage capacity
Unlimited devices attached to a single plan in many tiers. Current limitations to be aware of:
Focus on full-system backups over very granular “pick a few folders” use cases.
No dedicated mobile-device backup client yet
If your main requirement is protecting entire PCs, servers, and OneDrive, these constraints are rarely a problem. If you need deep, per-folder backup policies for heterogeneous environments, a hybrid approach using both C2 and NAS-based tools may be best.
How Synology C2 Fits into a 3-2-1 Backup Strategy
Modern backup strategies still rely on the 3-2-1 rule: keep three copies of your data, on two different media types, with one copy off-site.
Synology C2 makes this straightforward:
Primary data lives on your endpoints and NAS.
Secondary copies live on local NAS volumes or external drives, created with Synology’s Hyper Backup or similar tools.
Off-site copies reside in C2 Backup, ensuring your data survives local disasters, theft, or major outages.
Combined with scheduled, automated jobs, this creates a resilient, business-grade backup architecture without excessive complexity.
Work with a Synology Backup Specialist: Epis Technology
Epis Technology helps businesses design, deploy, and operate Synology-based backup and recovery environments that use both on-premises NAS and Synology C2 cloud services. The team focuses on building hybrid architectures that protect endpoints, servers, NAS volumes, Microsoft 365, and mission-critical applications under a single, centralized strategy. They combine Synology Active Backup, Hyper Backup, large-capacity NAS, and C2 Backup to deliver scalable, secure, and high-performance protection tailored to your growth. With ongoing monitoring, policy tuning, and disaster-recovery planning, Epis Technology ensures your Synology environment is not just installed, but continuously ready for real-world incidents.
Best Practices for Deploying Synology C2 Backup
1. Classify Data and Recovery Objectives
Begin by mapping your workloads:
User laptops and desktops
File servers and application servers
NAS-hosted shares and archives
Microsoft 365 / OneDrive data
Define RPO (how much data you can afford to lose) and RTO (how fast you must recover) for each category, then align them with C2 backup frequency and retention policies.
2. Combine Local NAS and Cloud Backup
Use Synology NAS for fast local restores and Synology C2 as your off-site layer:
Run frequent local backups (e.g., every hour) to the NAS.
Use C2 Backup for daily or near-daily off-site copies.
Reserve cloud storage for critical systems and data sets
This hybrid model balances speed, resilience, and cost.
3. Leverage Versioning and Scheduled Backups
Configure:
Daily or more frequent schedules during business hours
Multiple restore points (versions) to protect against silent corruption
Triggers such as PC startup, lock screen, or log-out for endpoints that are not always online
4. Test Restores Regularly
A backup that has never been tested is a risk. At least quarterly:
Perform file-level restore tests from C2 to a sandbox machine.
Simulate an endpoint failure and validate full-system recovery.
Verify that encryption keys and credentials are documented and accessible during an incident.
When Synology C2 Is the Right Choice
Synology C2 is especially compelling if:
You already rely on Synology NAS as a central storage or backup platform.
You need image-level backup and disaster recovery for Windows/macOS endpoints.
You want integrated protection for OneDrive and Microsoft 365 workloads.
You prefer a privacy-focused provider with strong client-side encryption
For organizations that want an end-to-end Synology stack from on-premises NAS to cloud backup, partnering with specialists like Epis Technology can turn Synology C2 from a standalone service into a complete, resilient data-protection strategy.