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Performance history for servers

This sub-topic of Performance history for Storage Spaces Direct describes in detail the performance history collected for servers. Performance history is available for every server in the cluster.

Note

Performance history cannot be collected for a server that is down. Collection will resume automatically when the server comes back up.

Series names and units

These series are collected for every eligible server:

Series Unit
clusternode.cpu.usage percent
clusternode.cpu.usage.guest percent
clusternode.cpu.usage.host percent
clusternode.memory.total bytes
clusternode.memory.available bytes
clusternode.memory.usage bytes
clusternode.memory.usage.guest bytes
clusternode.memory.usage.host bytes

In addition, drive series such as physicaldisk.size.total are aggregated for all eligible drives attached to the server, and network adapter series such as networkadapter.bytes.total are aggregated for all eligible network adapters attached to the server.

How to interpret

Series How to interpret
clusternode.cpu.usage Percentage of processor time that is not idle.
clusternode.cpu.usage.guest Percentage of processor time used for guest (virtual machine) demand.
clusternode.cpu.usage.host Percentage of processor time used for host demand.
clusternode.memory.total The total physical memory of the server.
clusternode.memory.available The available memory of the server.
clusternode.memory.usage The allocated (not available) memory of the server.
clusternode.memory.usage.guest The memory allocated to guest (virtual machine) demand.
clusternode.memory.usage.host The memory allocated to host demand.

Where they come from

The cpu.* series are collected from different performance counters depending on whether or not Hyper-V is enabled.

If Hyper-V is enabled:

Series Source counter
clusternode.cpu.usage Hyper-V Hypervisor Logical Processor > _Total > % Total Run Time
clusternode.cpu.usage.guest Hyper-V Hypervisor Virtual Processor > _Total > % Total Run Time
clusternode.cpu.usage.host Hyper-V Hypervisor Root Virtual Processor > _Total > % Total Run Time

Using the % Total Run Time counters ensures that performance history attributes all usage.

If Hyper-V is NOT enabled:

Series Source counter
clusternode.cpu.usage Processor > _Total > % Processor Time
clusternode.cpu.usage.guest zero
clusternode.cpu.usage.host same as total usage

Notwithstanding imperfect synchronization, clusternode.cpu.usage is always clusternode.cpu.usage.host plus clusternode.cpu.usage.guest.

With the same caveat, clusternode.cpu.usage.guest is always the sum of vm.cpu.usage for all virtual machines on the host server.

The memory.* series are (COMING SOON).

Note

Counters are measured over the entire interval, not sampled. For example, if the server is idle for 9 seconds but spikes to 100% CPU in the 10th second, its clusternode.cpu.usage will be recorded as 10% on average during this 10-second interval. This ensures its performance history captures all activity and is robust to noise.

Usage in PowerShell

Use the Get-ClusterNode cmdlet:

Get-ClusterNode <Name> | Get-ClusterPerf

Additional References