Define the symptom
Record when the problem occurs, which applications are affected and whether the issue is CPU, memory, disk or network related. Capture the VM size and operating system before making changes.
Use Azure Monitor signals
Review CPU, disk and network metrics over the incident window. Look for sustained saturation versus short spikes. A single high metric does not establish the root cause.
Run performance diagnostics
Azure performance diagnostics can collect data and provide insights for high CPU, memory and disk usage. Use the resulting report to guide the next test rather than treating it as an automatic fix.
Correlate with Windows counters
For Windows workloads, correlate Azure metrics with Performance Monitor counters and application logs. This can reveal whether high disk latency is caused by a storage workload or an application queue.
Check recent changes
Review VM resize operations, application deployments, Windows updates, scheduled tasks, backup jobs and security scans. A performance incident often starts with a change that happened shortly before the symptom.
Validate the remediation
After a change, monitor the same metrics for a representative period and compare them with the baseline. Document the evidence used to close the incident.
Useful commands
Get-Counter '\Processor(_Total)\% Processor Time'
Get-Counter '\Memory\Available MBytes'
Get-Counter '\LogicalDisk(*)\Avg. Disk sec/Read'What good troubleshooting looks like
Use evidence before configuration changes. Record the symptom, test result, change made and validation result so another engineer can repeat the procedure.
Symptom → hypothesis → direct test → controlled change → validation → documentation
Frequently asked questions
What should I check first?
Start with the exact failed path or dependency and test it directly before changing configuration.
Should I change production configuration immediately?
No. Capture the current state first and make one controlled change at a time.
How should I document the fix?
Record the symptom, commands, result, configuration change and validation result.
Related TechRunbook guides
Primary reference
This guide was independently written for TechRunbook. Technical details were checked against current Microsoft documentation. Microsoft Learn reference →
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