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Overview

This page covers common Instance HA issues encountered by project users — instances that did not recover, notifications stuck in error or running states, and protection settings that are not visible in the Dashboard. For platform-level issues such as monitor failures or engine misconfiguration, refer to the Instance HA Admin Troubleshooting guide.
Prerequisites
  • Project access to the Polystack Dashboard or CLI
  • Knowledge of the affected instance IDs and the compute host involved

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Common Issues

Cause: Instance HA protection may not be enabled for the instance, the compute host may not be registered in any segment, or the segment may be disabled.Resolution:Confirm the segment is enabled and the host is registered:
Check segment status
List hosts in segment
If the failed host is missing from the segment, contact your administrator to register it. Your administrator can configure this through the deployment console. If the segment is disabled (enabled: False), your administrator must re-enable it.
After the root cause is resolved, manually evacuate the instance to restore service:
Manual evacuation
Cause: Automatic recovery failed. Common causes: insufficient capacity on remaining hosts, an instance stuck in ERROR state that the engine cannot recover, or a network issue during evacuation.Resolution:
Show notification detail
Review the payload for specific failure information. Then check instance state:
Show instance status
If the instance is in ERROR state, attempt a manual reset and evacuation:
Reset instance state
Manually evacuate
Contact your administrator if the instance cannot be recovered through the above steps. Your administrator can configure this through the deployment console.
Cause: The recovery engine is waiting for the target host to accept the instance, a workflow step has timed out, or the target host is under load.Resolution:Check how long the notification has been in running state:
Show notification timestamps
If the notification has been running for more than 10 minutes, contact your administrator. They can inspect the Instance HA engine logs and reset the workflow if it has genuinely stalled. Your administrator can configure this through the deployment console.
Cause: No failover segment has been created for your environment, or the segments that exist have not been made accessible to your project.Resolution: Contact your Polystack administrator and request that a failover segment be created and that the compute hosts used by your project be registered. Your administrator can configure this through the deployment console. See the Instance HA Admin Guide — Failover Segments for the configuration steps.
Cause: The compute service cannot confirm the instance state because the host is unreachable. This is expected immediately after a host fault is detected.Resolution: Wait for the recovery workflow to complete. The instance transitions from UNKNOWN → MIGRATING → BUILD → ACTIVE as recovery proceeds.If the instance remains UNKNOWN for more than 5 minutes without a recovery notification being created, verify that the failed host is registered in an enabled segment and that the host monitor can reach the Instance HA notification endpoint.
Cause: The auto recovery method placed the instance on any available host rather than a specific preferred host. This is expected behaviour for the auto method.Resolution: If your workloads require guaranteed placement on specific hosts, ask your administrator to configure a segment with reserved_host or rh_priority recovery method and designate the preferred host as a reserved standby.

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Manual Recovery Procedure

If automatic recovery fails, use the following procedure to restore service manually.

Identify the affected instances

Find instances on the failed host

Reset instance state if stuck in ERROR

Reset instance state

Evacuate to a healthy host

Evacuate to a specific host
Omit --host to let the scheduler choose any available host in the segment:
Evacuate to any available host

Verify recovery

Confirm instance is ACTIVE
Instance shows ACTIVE and the host field reflects the new compute node.

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Next Steps

Monitoring Status

Track live and historical recovery notifications.

Recovery Workflows

Understand recovery methods and workflow stages.

Instance HA Admin Troubleshooting

Administrator-level troubleshooting for monitors, engine failures, and capacity issues.

Compute User Guide

Manage and recover instances manually using core compute operations.