Cluster

The Cluster page shows you an overview of the high-availability cluster. This page is divided into four sections, offering you details on the cluster status, host utilization, and recent system logs; you can also manage the cluster on this page.

High-availability Cluster Status

On the top of the page is the overall status of the high availability cluster. You can check if the system is running as expected, and solutions are provided when there is any system abnormality:

Status Description
Healthy The cluster is healthy. Data is being replicated between the hosts, and the auto failover feature is available.
Processing They system is processing certain operations, such as data replication, volume repair/expansion, and more. The auto failover feature will not be available.
Updating The system or the package is updating. The auto failover feature will not be available.
Warning The system has detected errors in the cluster, but the services may still be running. The auto failover may be unavailable, and the errors must be addressed as soon as possible.
Critical The system has detected one or more critical errors in the cluster, and the hosts are not able to run the usual services. All errors must be addressed as soon as possible. The system may encounter a split-brain error, usually caused by network failure, and would fail to determine which of the hosts runs as the active server. In this case, all services will be suspended to avoid further data inconsistency until the issues are resolved.

Note:

Abnormal Status

Here are some common abnormal statuses indicating errors in the system. If more than one error is detected, only the one that most requires your attention will be displayed and should be resolved as soon as possible.

Warning/Error Description Suggested Solution
Monitored service error An error occurred on one or more monitored services. The available monitored services include SMB, AFP, FTP, NFS and iSCSI LUN. Sometimes the errors are temporary and can be resolved by restarting the server. Contact Synology Technical Support if the problem persists.
Storage space degraded A storage space (e.g. RAID Group, Disk Group, volume, iSCSI LUN and SSD cache) on the active or passive server is degraded. Details can be found on the Storage page of Synology High Availability. Replace the failed drives on the host and repair the volume/LUN in the Storage tab.
Storage space crashed A storage space (e.g. RAID Group, Disk Group, volume, iSCSI LUN and SSD cache) on the passive server crashed. Details can be found on the Storage page of Synology High Availability. Replace the failed drives on the passive server and repair the volume/LUN in the Storage tab.
Failed to detect passive server This error might occur because the passive server is offline or the active and passive servers cannot connect via the Heartbeat connection. In this case, the auto failover feature will be unavailable. Make sure the passive server is powered on, and the cluster and Heartbeat connections are properly connected between the hosts.
Data cannot be replicated to passive server This error might occur due to a storage volume or drive failure. In this case, the auto failover feature will be unavailable. Details can be found on the Storage page of Synology High Availability. Check the storage status of the passive server, and repair the failed drives if there are errors detected.
No passive server in the cluster If the passive server is removed from the high-availability cluster, this status will be displayed. In this case, the auto failover feature will be unavailable. Click Manage > Add passive server to add a passive server to form a cluster. When you have added the passive server, full data synchronization will be required and the auto failover feature will only be available until the synchronization is done.

High-availability Cluster Information

This section displays the basic information of the cluster connection with a simulated illustration. A warning/critical icon will also be shown when there is a system error.

You can find the Heartbeat connection status, transfer speed as well as latency in this section as well.

To manage the high-availability cluster:

There are two buttons below the cluster information section for you to operate on the cluster with:

  1. Power button:
  2. Manage: 

Note:

Host utilization

In this grid, you can monitor the important resource usage of the two hosts. Theoretically, the resource usage of the hosts are correlated, but the statistics of the active server would usually be higher, as it is responsible for running all services. You can check the following usage information in this part:

Recent important activities

The 5 latest logs will be listed in this section for you catch up with the recent cluster activities at a glance. The information includes the date and time, user, and the event detail. This section is useful when events happen and you would like to trace the most recent activities in the cluster.
For complete log records, refer to the Log tab.