How to Sync Multiple Synology NAS with Drive

How to Sync Data Between Multiple Synology NAS Using Synology Drive

Keeping multiple Synology NAS systems synchronized across offices, remote sites, or data centers requires more than copying files on a schedule. Modern organizations need real-time collaboration, consistent permissions, and secure cross-site access without compromising performance.

With Synology Drive Server and Synology Drive ShareSync, you can build a near real-time synchronization framework that keeps Team Folders aligned across locations while respecting bandwidth, security, and policy requirements.

This guide explains how to properly design, configure, and optimize NAS-to-NAS synchronization using Synology Drive.

Understanding the Architecture

A properly designed multi-NAS sync environment includes three core components:

Synology Drive Server

Installed from Package Center, this enables Drive services and manages Team Folders. Learn how Synology Drive Server enables enterprise file synchronization

Team Folders

Existing shared folders must be enabled as Team Folders in the Drive Admin Console. Only enabled Team Folders can participate in ShareSync.

Synology Drive ShareSync

This runs on the connecting NAS and establishes synchronization with a remote Drive Server.

In most deployments, one NAS acts as the central hub, while other NAS devices connect as satellites. However, peer-to-peer and bidirectional designs are also supported.

Recommended Sync Topologies

Team Folder structure and ShareSync topology design is essential for reliable multi-NAS synchronization. View complete guide to Synology Drive Team Folders and ShareSync topologies.

Hub-and-Spoke

A central NAS hosts core data. Branch offices connect via ShareSync. Ideal for multi-branch businesses.

Bidirectional Pair

Two sites actively collaborate with two-way synchronization. Suitable for headquarters and disaster recovery locations.

One-Way Offsite Mirror

• Primary NAS syncs to a remote NAS in download-only mode. Useful for warm standby systems.
• Choosing the correct topology depends on collaboration patterns and recovery requirements.

Step 1: Prepare Both NAS Devices

Before configuring synchronization, ensure both systems are properly prepared.

• Update DSM to the latest stable release.
• Install the latest Synology Drive Server package.
• Confirm shared folder structure is clearly organized.

Only folders that require synchronization should be selected. Avoid syncing entire volumes unnecessarily.

For better security, create a dedicated service account for ShareSync instead of using the default administrator account. Assign it only the required permissions.

Step 2: Install Synology Drive Server and Enable Team Folders

On each NAS:

1. Open Package Center

2. Install Synology Drive Server

3. Launch Synology Drive Admin Console

4. Navigate to Team Folder

5. Enable the shared folders that require synchronization

Enabling versioning within Team Folders is strongly recommended. This allows file rollback in case of accidental overwrites. 

Step 3: Configure Synology Drive ShareSync

On the NAS that will connect to another NAS:

1. Launch Synology Drive ShareSync

2. Click Add Connection

3. Enter the remote NAS IP address, FQDN, or QuickConnect ID

4. Provide credentials for the remote system

5. Test and confirm connectivity

Ensure port 6690/TCP is open between both NAS devices. This port is required for Drive file synchronization.

After connection, select which Team Folders to synchronize. Explore Synology Drive client features and file synchronization capabilities

Step 4: Configure Sync Direction

Each Team Folder can be customized.

• Download-only mode
  The remote NAS acts as the source of truth.
• Upload-only mode
  The local NAS pushes changes to the remote system.
• Two-way sync
  Both systems can modify files. Use carefully and establish clear file ownership policies to avoid conflicts.

In collaborative environments, two-way sync is common. For disaster recovery mirrors, download-only mode is preferred.

Step 5: Fine-Tune Filters and Permissions

For performance optimization, configure file filters.

• Exclude temporary files
• Exclude large archive formats
• Exclude system or cache files

You may also configure permission synchronization. If both NAS devices use centralized directory services such as LDAP or Active Directory, permission syncing is more predictable.

Granular filtering keeps real-time sync efficient and reduces unnecessary bandwidth usage.

Monitoring and Troubleshooting

Regular monitoring ensures synchronization remains healthy.

• Check ShareSync dashboard status.
• Monitor DSM Resource Monitor for CPU and network load.
• Review sync logs for errors or stalled transfers.

Common issues include:

• Connection failures due to firewall blocks
• Permission mismatches between NAS units
• Large file transfers stalling on unstable WAN links

For extremely large datasets or archival transfers, consider using Hyper Backup instead of real-time sync. See what causes Synology Drive sync errors and how to fix them

Network and Security Best Practices

When syncing across sites, security and transport matter.

• LAN-based sync offers highest performance.
• Site-to-site VPN is preferred for cross-location security.
• Direct port forwarding should be carefully evaluated.
• Use HTTPS for DSM access.
• Enable 2-factor authentication for administrative accounts.
• Restrict firewall rules to known IP ranges.
• Avoid exposing administrative interfaces directly to the internet.

When Not to Use Synology Drive ShareSync

ShareSync is not a backup solution. Don’t confuse sync with backup when protecting Synology NAS data, see here why. If a file is deleted on one NAS, it is deleted on the other.

For ransomware protection, accidental deletions, or long-term retention, use Snapshot Replication or Hyper Backup in addition to ShareSync.

Real-time synchronization improves availability, but it does not replace layered data protection.

Best Practices for Reliable Multi-NAS Sync

• Keep DSM and Drive packages updated.
• Enable only necessary Team Folders.
• Separate active data from archival data.
• Pair sync with independent backup.
• Test failover scenarios periodically.

A well-designed deployment combines live sync with proper backup strategy.

About Epis Technology

Epis Technology specializes in architecting secure, scalable Synology NAS environments for distributed teams and enterprise organizations. We design hub-and-spoke, bidirectional, and hybrid synchronization models that integrate real-time sync with backup, disaster recovery, and compliance-driven policies. From deployment to ongoing optimization, Epis Technology ensures your Synology infrastructure remains secure, resilient, and aligned with business continuity requirements.