Collect performance counters from virtual machine with Azure Monitor

Performance counters provide insight into the performance of virtual hardware components, operating systems, and workloads. Collect counters from both Windows and Linux virtual machines using a data collection rule (DCR) with a Performance Counters data source.

Details for the creation of the DCR are provided in Collect data from VM client with Azure Monitor. This article provides additional details for the Performance Counters data source type.

Note

To work with the DCR definition directly or to deploy with other methods such as ARM templates, see Data collection rule (DCR) samples in Azure Monitor.

Configure performance counters data source

Create the DCR using the process in Collect data from virtual machine client with Azure Monitor. On the Collect and deliver tab of the DCR, select Performance Counters from the Data source type dropdown. Select from a predefined set of objects to collect and their sampling rate. The lower the sampling rate, the more frequently the value is collected.

Select Custom to specify an XPath to collect any performance counters not available with the Basic selection. Use the format \PerfObject(ParentInstance/ObjectInstance#InstanceIndex)\Counter.

Tip

If the counter name contains an ampersand (&), replace it with &. For example, \Memory\Free & Zero Page List Bytes.

Warning

Be careful when manually defining counters for DCRs that are associated with both Windows and Linux machines, since some Windows and Linux style counter names can resolve to the same metric and cause duplicate collection. For example, specifying both \LogicalDisk(*)\Disk Transfers/sec (Windows) and Logical Disk(*)\Disk Transfers/sec (Linux) in the same DCR will cause the Disk Transfers metric to be collected twice per sampling period.

This behavior can be avoided by not collecting performance counters in DCRs that don't specify a platform type. Ensure that Windows counters are only included in DCRs associated with Windows machines, and Linux counters are only included in DCRs associated with Linux machines.

Note

Microsoft.HybridCompute (Azure Arc-enabled servers) resources can't currently be viewed in Metrics Explorer, but their metric data can be acquired via the Metrics REST API (Metric Namespaces - List, Metric Definitions - List, and Metrics - List).

Add destinations

Performance counters can be sent to a Log Analytics workspace where it's stored in the Perf table and/or Azure Monitor Metrics (preview) where it's available in Metrics explorer. Add a destination of type Azure Monitor Logs and select a Log Analytics workspace. No further details are required for Azure Monitor Metrics (preview) since this is stored at the subscription level for the monitored resource.

Note

For Linux, using Azure Monitor Metrics as the only destination is supported in v1.10.9.0 or higher.

Verify data collection

To verify that data is being collected in the Log Analytics workspace, check for records in the Perf table. From the virtual machine or from the Log Analytics workspace in the Azure portal, select Logs and then click the Tables button. Under the Virtual machines category, click Run next to Perf.

To verify that data is being collected in Azure Monitor Metrics, select Metrics from the virtual machine in the Azure portal. Select Virtual Machine Guest (Windows) or azure.vm.linux.guestmetrics for the namespace and then select a metric to add to the view.

Next steps

• Learn more about Azure Monitor Agent.
• Learn more about data collection rules.