Synology NAS Snapshot Replication Failed: How to Fix It

Q: Why does my Synology snapshot replication keep failing?

Common causes include network connectivity issues, insufficient storage space on the destination NAS, incorrect user permissions, or outdated DSM firmware. Check each of these factors systematically to identify the root cause.

Q: How much storage space do I need for snapshot replication?

You need at least 10-20% free space on the destination volume, plus enough room for the snapshot data itself. The exact requirement depends on your retention policy and how much data changes between snapshots.

Q: Can I run snapshot replication over the internet?

Yes, but you need to configure proper port forwarding, SSL certificates, and VPN connections for security. Direct internet replication is not recommended without proper encryption and access controls.

Q: What happens if my destination NAS goes offline during replication?

The replication will fail and retry according to your schedule settings. Once the destination comes back online, replication will resume from the last successful snapshot, ensuring no data loss.

Q: How do I check replication logs for detailed error information?

Go to Log Center in DSM and filter for 'Snapshot Replication' events. These logs provide detailed error codes and timestamps that can help diagnose specific issues with your replication tasks.

Abstract

The 'Snapshot replication failed' error on your Synology NAS occurs when the system cannot complete the automatic backup process to a destination device. This typically happens when the target NAS is offline, unreachable over the network, or has run out of storage space.