How do I resolve data synchronization issues in an HA cluster?
Last modified date:
2025-07-24
Applicable Products
- QuTS hero h5.3.0 or later
- High Availability Manager
Scenario
In a high-availability (HA) cluster, if data synchronization from the active node to the passive node fails, High Availability Manager may display a synchronization error on the Cluster page, and the cluster may lose fault tolerance or behave abnormally.
Solution
- Check the physical heartbeat connection.
- Verify the network cable status: Ensure the network cable used for the heartbeat connection is securely connected and not loose, damaged, or oxidized.
- Use a direct connection: Make sure the heartbeat cable directly connects the two nodes without passing through any network devices (such as switches).
- Check the passive node status.
- Verify the passive node is online: If the passive node is powered off, unresponsive, or disconnected from the network, synchronization will fail. Make sure it is powered on and properly connected to the active node.
- Check storage health: If the passive node has disk issues or a faulty storage pool, synchronization will be blocked. Go to Storage Manager to check the disk and pool status on the passive node.
- Check system load and resources.
- System resource bottlenecks: If either node experiences high CPU or memory usage, synchronization performance may be affected. Use Resource Monitor to check the system load.
- Heavy background tasks: Tasks such as snapshot creation, RAID rebuilding, or large data transfers may delay synchronization. Wait until these tasks are complete and check again.
- Review system logs for error messages.
- Open QuLog Center and review system logs related to high availability to identify the root cause of connection or synchronization issues.
- Restart the passive node.
- If the hardware and network are functioning correctly but synchronization is still stuck, try safely restarting the passive node to trigger synchronization.
If you have tried all the above steps and still cannot resolve the issue, contact QNAP Customer Service for further assistance.
