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Overview

This page covers common Resource Optimizer issues encountered by operators — audits that produce empty plans, audits stuck in ONGOING, migrations that fail during execution, and plans that revert after completion. For platform-level issues such as Decision Engine failures or data source connectivity, see the Admin Troubleshooting guide.

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Common Issues

Cause: The cluster is already optimally placed for the selected goal — the strategy found no hosts below the utilization threshold and no migrations are recommended.Resolution:Check current host utilization to confirm whether consolidation is genuinely needed:
Check per-host utilization
openstack hypervisor list --long
If all hosts show healthy, even utilization — this is expected behaviour. No action is needed.If hosts appear imbalanced but no plan was generated, the strategy threshold may be too conservative:
Create audit with lower threshold
watcher audit create \
  --goal server_consolidation \
  --parameter threshold=0.1 \
  --name lower-threshold-audit
The default consolidation threshold is 0.2 (20%). Lowering it to 0.1 (10%) means more hosts qualify as underutilized and are included in the migration plan.
Cause: The Decision Engine is waiting for metric data from a slow or unavailable data source (Prometheus or Telemetry).Resolution:
Check audit status and duration
watcher audit show <audit-uuid> \
  -f value -c state -c created_at
If the audit has been ONGOING for more than 5 minutes, contact your administrator to check Decision Engine and data source connectivity. Your administrator can configure this through XDeploy.For non-telemetry goals (e.g., server_consolidation, zone_migration), audits should complete within 30–90 seconds. Longer durations indicate a data collection issue.
Cause: A live migration failed — commonly due to insufficient memory on the target host, a CPU model incompatibility between source and destination hosts, or a storage connectivity issue.Resolution:
Show failed action details
watcher action show <action-uuid> -f json
Review the fault field for the specific migration error. Common errors:
ErrorCauseFix
No valid host foundTarget host has insufficient capacityAdd compute capacity or adjust plan
CPU compatibilityCPU model mismatch between hostsConfigure cpu_mode=custom on all hosts
Disk not foundInstance uses local disk (not shared storage)Verify instance uses shared storage backend
After resolving the root cause, create a new audit to generate a fresh plan.
Cause: A previous action in the plan failed, causing the Applier to halt and cancel all remaining actions automatically.Resolution: Review the failed action to identify the root cause:
List actions and find the failed one
watcher action list \
  --action-plan <action-plan-uuid> \
  -f table -c uuid -c action_type -c state
Fix the root cause (capacity, CPU compatibility, storage), then run a new audit to generate an updated plan reflecting the current cluster state.
Cause: Another process — the compute scheduler placing new instances, auto-scaling, or manual migrations — is placing instances back on hosts that were just emptied by the optimization.Resolution: Coordinate with team members performing manual migrations during optimization windows. Consider applying compute host aggregates or availability zone constraints to prevent the scheduler from re-populating hosts that were intentionally consolidated.

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Diagnostic Commands

List all audits with states
watcher audit list \
  -f table -c uuid -c name -c state -c created_at
Show full audit detail
watcher audit show <audit-uuid> -f json
List action plans with states
watcher actionplan list \
  -f table -c uuid -c state -c audit_uuid
Show individual action failures
watcher action show <action-uuid> -f json

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Next Steps

Run an Audit

Create a new audit after resolving the issue.

Audit History

Review past audits to identify recurring patterns.

Admin Troubleshooting

Platform-level diagnostics for Decision Engine and data source failures.

Compute Admin Guide

Verify shared storage and live migration capability for optimization actions.