Windows Server 2019 Insider Preview Build 17666 released

The next version of Windows Server is expected to go online this fall and may be called Windows Server 2019, which belongs to the RedStone 5 development branch. Following the release of Build 17650 a few weeks ago, today Microsoft has again released the Windows Server 2019 Insider Preview Build 17666, while also releasing the Windows 10 SDK Insider Preview Build 17666.

What’s new?

Performance history for Storage Spaces Direct

This build improves the Get-ClusterPerformanceHistory cmdlet to be more scripting-friendly. It’s now convenient to pipe performance history into utility cmdlets like Sort-ObjectWhere-Object, and Measure-Object so you can quickly find the average or peak value, filter values, plot trend lines, run outlier detection, and more.

This build adds performance history for the Storage Spaces Direct cache for reads (% hit rate) and writes (% full), as well as the CSV in-memory read cache (% hit rate). These new series are available per-server and in aggregate.

Some performance history series have changed names in this build for greater clarity and consistency—for example, Node.Cpu.Usage is now ClusterNode.Cpu.Usage. Note that this change will result in some blank charts in Windows Admin Center until its next update.

Delimit volume allocation with Storage Spaces Direct

New cmdlets, provided in this build, simplify the management of volumes with delimited allocation. Use Get-StorageScaleUnit to see fault domains; follow associations to/from Get-VirtualDisk to see the current allocation; and set or modify allocation by using friendly names for fault domains. For more details, see the links under “Insider Preview content” on