A central hub of Azure cloud migration services and tools to discover, assess, and migrate workloads to the cloud.
Hello Bagavan Muniandy – it looks like you’re running into two separate but related issues in Azure Migrate. Here’s how you can troubleshoot each:
- Internal system error during assessment • Go into your Azure Migrate project → Servers, databases and web apps → Migration tools → Jobs. Find the failed assessment job and note the exact error code/message. • Common causes: – Appliance can’t fetch perf data or metadata from your source (VMware vCenter, Hyper-V host or physical server). – Credentials on the appliance don’t have the required privileges (e.g. VMware guest-operations, WinRM/SSH). – Network or firewall blocking ports: • VMware: HTTPS 443 + port 902 for performance metrics • Hyper-V/WinRM: port 5985 • Linux/SSH: port 22
– vCenter statistics level is set too low (must be level 3 for performance data). • Remediation steps:- Validate appliance → source connectivity and credentials.
- If VMware, bump vCenter stats to level 3 and wait up to 24 hrs for data to appear.
- Ensure outbound port 443 is open to Azure Migrate service URLs.
- Re-run (recalculate) the assessment.
- “Performance coverage” shows “Not applicable” • That status appears when you run a Quick (static) assessment or select a zero-day performance window. In that mode, Azure Migrate only does a config-data assessment and doesn’t collect any perf counters, so “Perf coverage” = N/A. • To get an actual perf-coverage percentage:
- Create or recalc the assessment with a performance-based window (for example, 7 days).
- Keep your VMs powered on and connected to the appliance for that full duration.
- Verify in the portal that each VM’s Azure Migrate connection status is Connected and that no perf counters are missing.
- Once the window closes, recalculate – you’ll see a % of time data was successfully collected under “Performance coverage.”
Follow-up questions to pin it down:
• What exact error code/message do you see in the Azure Migrate job log when the “internal error” happens?
• Which hypervisor or server type are you assessing (VMware, Hyper-V, physical)?
• Did you run the assessment as a Quick (0 day) assessment or choose a performance window? If the latter, how long was it?
• Have you confirmed vCenter stats level 3 (for VMware) and that ports 443/902 (or 5985/SSH) are open in both directions?
References
– Troubleshoot assessment errors (missing perf data, internal errors): https://docs.microsoft.com/azure/migrate/troubleshoot-assessment
– Common issues in creating/updating/exporting assessments:
https://supportabilityhub.microsoft.com/solutions/apollosolutions/.../creating-updating-and-exporting-assessments
– Azure Migrate perf-data requirements (vCenter stats level, ports): https://docs.microsoft.com/azure/migrate/troubleshoot-assessment#common-assessment-errors
Hope this helps. Let me know if you need any assistance, thanks