Use a performance counter to detect Hyper-V bottlenecks

Performance counters ship with Windows OS and are used to check Hyper-V hosts and VMs for performance problems with network, storage, CPU and memory resources.

Although Hyper-V Manager doesn't provide any options for detecting bottlenecks on Hyper-V hosts and VMs, you can use third-party tools to detect issues related to network, storage, CPU and memory. Another option is to use the performance counters that Windows OS ships with to detect bottlenecks on Hyper-V hosts.

There are various performance counters available to find issues on Hyper-V hosts and VMs, depending on the issue you're facing. For example, if a Hyper-V host isn't operating normally or takes too much time responding to Hyper-V calls from VMs and remote machines, you might want to use the Hyper-V Hypervisor Logical Processor (_Total)\% Total RunTime performance counter to ensure the Hyper-V host has enough processing power available to process requests quickly. If the logical processor runtime count value is above 85%, the Hyper-V host is overloaded and requires immediate attention.

Similarly, if you need to check whether the memory assigned to VMs is sufficient, you can use the Memory\Available Mbytes performance counter. If the available memory value shows low consistently, you might want to assign more memory to VMs or increase the maximum memory setting if you're using dynamic memory.

To detect storage latencies or troubleshoot storage-related issues in Hyper-V, use physical disk performance counters, such as Physical Disk\Avg. Disk Sec/Read, Physical Disk\Avg. Disk sec/Write, Physical Disk\Avg. Disk read queue length and Physical Disk\Avg. Disk write queue length. If you find greater storage latencies, you can buy additional or fast storage or move VMs to available storage. You can also enable Storage Quality of Service if the Hyper-V host is running on Windows Server 2012 or later OSes, which allows you to fine-tune storage policies for VMs.

There are various performance counters available to find issues on Hyper-V hosts and VMs, depending on the issue you're facing.

To detect network bottlenecks, there are two performance counters available: Physical NIC Bytes/Sec, used to detect network performance for the Hyper-V host, and the Hyper-V Virtual Network Adapter Bytes/Sec performance counter, which can be used to see how a VM network is performing.

You can use the above performance counters to detect bottlenecks in various Hyper-V components, which ultimately helps you get to the root cause of the problem.

Next Steps

Use these Hyper-V performance-tuning tips

Improve VM networking performance

Develop a VM load-balancing strategy to avoid mistakes

Dig Deeper on Microsoft Hyper-V management